1. trig help much appreciated! :))

    1. Find the complete exact solution of sin x = . 2. Solve cos 2x – 3sin x cos 2x = 0 for the principal value(s) to two decimal places. 3. Solve tan2 x + tan x – 1 = 0 for the principal value(s) to two decimal places. 4. Prove that tan2  – 1 + cos2 

    asked by suzy on August 16, 2013
  2. MATH

    1.)Find the exact solution algebriacally, if possible: (PLEASE SHOW ALL STEPS) sin 2x - sin x = 0 2.) GIVEN: sin u = 3/5, 0 < u < ï/2 Find the exact values of: sin 2u, cos 2u and tan 2u using the double-angle formulas. 3.)Use the half-angle formulas to

    asked by MAKITA on April 11, 2009
  3. trigonometry

    5.Find the complete exact solution of sin x = -√3/2. 10. Solve cos 2x – 3sin x cos 2x = 0 for the principal value(s) to two decimal places. 12. Solve tan^2x + tan x – 1 = 0 for the principal value(s) to two decimal places. 19.Prove that tan^2a – 1

    asked by Jose on December 16, 2012
  4. trigonometry

    5. Find the complete exact solution of sin x = -√3/2. 9. Solve cos 2x – 3sin x cos 2x = 0 for the principal value(s) to two decimal places. 21. Solve tan^2x + tan x – 1 = 0 for the principal value(s) to two decimal places. 22. Prove that tan^2a –

    asked by eemily on December 13, 2012
  5. TRIG!

    Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6 x=1 - (3/4)sin^2 2x work on one side only! Responses Trig please help! - Reiny, Monday, February 23, 2009 at 4:27pm LS looks like the sum of cubes sin^6 x + cos^6 x = (sin^2x)^3 +

    asked by hayden on February 24, 2009
  6. Trig hep, please? Thank you!

    1. Find the exact value of sin(195(degrees)) 2. If cot2(delta)=5/12 with 0(

    asked by Michelle on August 18, 2013
  7. Trigonometry

    4. Find the exact value for sin(x+y) if sinx=-4/5 and cos y = 15/17. Angles x and y are in the fourth quadrant. 5. Find the exact value for cos 165degrees using the half-angle identity. 1. Solve: 2 cos^2x - 3 cosx + 1 = 0 for 0 less than or equal to x

    asked by Tiffany Enlow on April 10, 2009
  8. Math

    Evaluate *Note - We have to find the exact value of these. That I know to do. For example sin5π/12 will be broken into sin (π/6) + (π/4) So... sin 5π/12 sin (π/6) + (π/4) sin π/6 cos π/4 + cos π/6 sin π/4 I get all those steps. The part I am

    asked by Anonymous on November 25, 2007
  9. Calculus 12th grade (double check my work please)

    1.)Find dy/dx when y= Ln (sinh 2x) my answer >> 2coth 2x. 2.)Find dy/dx when sinh 3y=cos 2x A.-2 sin 2x B.-2 sin 2x / sinh 3y C.-2/3tan (2x/3y) D.-2sin2x / 3 cosh 3yz...>> my answer. 2).Find the derivative of y=cos(x^2) with respect to x. A.-sin (2x) B.-2x

    asked by anon on March 6, 2011
  10. math

    Use the exact values of the sin, cos and tan of pi/3 and pi/6, and the symmetry of the graphs of sin, cos and tan, to find the exact values of si -pi/6, cos 5/3pi and tan 4pi/3. I have found the answers to the first three using the special tables

    asked by jenny on August 24, 2011
  11. tigonometry

    expres the following as sums and differences of sines or cosines cos8t * sin2t sin(a+b) = sin(a)cos(b) + cos(a)sin(b) replacing by by -b and using that cos(-b)= cos(b) sin(-b)= -sin(b) gives: sin(a-b) = sin(a)cos(b) - cos(a)sin(b) Add the two equations:

    asked by Pablo on November 26, 2006
  12. Math- Trig

    1. Determine the exact value of cos^-1 (pi/2). Give number and explanaton. 2. Determine the exact value of tan^-1(sq. root 3). with explanation. 3. Determine exact value of cos(cos^-1(19 pi)). with explanation. 4. Determine the exact value of sin(sin^-1(20

    asked by Crystal on April 15, 2012
  13. Precalculus

    Solve Cos^2(x)+cos(x)=cos(2x). Give exact answers within the interval [0,2π) Ive got the equation down to -cos^2(x)+cos(x)+1=0 or and it can be simplified too sin^2(x)+cos(x)=0 If you could tell me where to go from either of these two, it would be great

    asked by Josh on February 24, 2012
  14. Calculus

    I need to find the exact solutions on the interval [0,2pi) for: 2sin^2(x/2) - 3sin(x/2) + 1 = 0 I would start: (2sin(x/2)-1)(sin(x/2)-1) = 0 sin(x/2)=1/2 and sin(x/2)=1 what's next? Ok, what angle has a sin equal to say 1/2 sin (x/2)=1 arc sin (1) = x/2

    asked by Jen on August 21, 2006
  15. math

    Use the exact values of the sin, cos and tan of pi/3 and pi/6, and the symmetry of the graphs of sin, cos and tan, to find the exact values of sin -pi/6, cos 5/3pi and tan 4pi/3. I have found the answers to the first three using the special tables sin pi/6

    asked by jenny on August 25, 2011
  16. algebra

    Can someone please help me do this problem? That would be great! Simplify the expression: sin theta + cos theta * cot theta I'll use A for theta. Cot A = sin A / cos A Therefore: sin A + (cos A * sin A / cos A) = sin A + sin A = 2 sin A I hope this will

    asked by Valerie on February 18, 2007
  17. precalc

    Find the exact value of each expression, if it exists: the -1 are representing the inverse functions! (a) sin -1 (-√2/2) (b) cos−1 (−1) (c) sin( 􏰀sin−1 (π)􏰁) (d) cos−1􏰀(cos􏰀(−4π􏰁􏰁/ 3)) (e) tan−1 (tan(0.6)) (f) cos−1(

    asked by help! on April 17, 2016
  18. Calculus - MathMate Please help

    ok, i tried to do what you told me but i cant solve it for c because they cancel each others out! the integral for the first one i got is [sin(c)cos(x)-cos(c)sin(x)+sin(x)+c] and the integral for the 2nd one i got is [-sin(c)cos(x)+cos(c)sin(x)-sin(x)+c] I

    asked by K on November 29, 2010
  19. Math

    1. Find the exact value of 2tan pi/12 / 1-tan^2 pi/12 root 3/3? 2. Given tanθ = -1/3 and with θ in quadrant IV, find the exact value of cos2(θ) 4/5 3. Exact value of cos^2 67.5 - sin^2 67.5 root3 /2 4. The expression cos 3θ can be rewritten as 1 -

    asked by mysterychicken on June 3, 2013
  20. Pre-Calc

    Hi, can someone please teach me how to solve this? Find the exact value of the trigonometric expression cos(89)sin(29)+sin(89)sin(29)

    asked by chizoba on August 13, 2016
  21. Precal

    I do not understand how to do this problem ((sin^3 A + cos^3 A)/(sin A + cos A) ) = 1 - sin A cos A note that all the trig terms are closed right after there A's example sin A cos A = sin (A) cos (A) I wrote it out like this 0 = - sin^6 A - cos^6 A +

    asked by Joe on January 14, 2010
  22. trig

    2sin(x)cos(x)+cos(x)=0 I'm looking for exact value solutions in [0, 3π] So I need to find general solutions to solve the equation. But do I eliminate cos(x), like this... 2sin(x)cos(x)+cos(x)=0 2sin(x)cos(x)= -cos(x) 2sin(x) = -1 sin(x) = -1/2 at 4pi/3

    asked by Alex on March 23, 2008
  23. trigonometry

    1) Find the exact value of the expression: tan−1(tan(−120651/47π))... How do you find Tan(-120651/47pi)? I don't know how to find exact values, if it's not a recognizable value. 2)Find a simplified expression for tan(sin−1(a/5))... Because tan = y/x

    asked by Dan on May 3, 2015
  24. calculus

    find max, min and saddle points of the give function f(x,y)=sin(x)+sin(y)+sin(x+y) 0

    asked by Help Please on March 10, 2012
  25. Algebra II

    Multiple Choice (theta) means the symbol 0 with the dash in it. 1.)Which expression is equivalent to tan(theta)-(sec(theta))/(sin(theta))? A.)-cot(theta) B.)cot(theta) C.)tan(theta)-cot(theta) D.)tan(theta)-sec^2(theta) 2.)Find the exact value of:cos 375

    asked by HotMath on June 9, 2011
  26. trig

    Reduce the following to the sine or cosine of one angle: (i) sin145*cos75 - cos145*sin75 (ii) cos35*cos15 - sin35*sin15 Use the formulae: sin(a+b)= sin(a) cos(b) + cos(a)sin(b) and cos(a+b)= cos(a)cos(b) - sin(a)sin)(b) (1)The quantity = sin(145-75) = sin

    asked by Paul C on November 26, 2006
  27. calculus

    Find complete length of curve r=a sin^3(theta/3). I have gone thus- (theta written as t) r^2= a^2 sin^6 t/3 and (dr/dt)^2=a^2 sin^4(t/3)cos^2(t/3) s=Int Sqrt[a^2 sin^6 t/3+a^2 sin^4(t/3)cos^2(t/3)]dt =a Int Sqrt[sin^4(t/3){(sin^2(t/3)+cos^2(t/3)}]dt=a Int

    asked by ms on September 18, 2013
  28. Trigonometry

    Solve the equation for exact solutions in the interval 0 ≤ x < 2π. (Enter your answers as a comma-separated list.) sin 2x cos x + cos 2x sin x = 0

    asked by Karen on October 22, 2014
  29. Trigonometry

    Solve the equation for exact solutions in the interval 0 ≤ x < 2π. (Enter your answers as a comma-separated list.) cos 2x cos x − sin 2x sin x = 0

    asked by Karen on October 22, 2014
  30. Maths

    Solve for x (exact solutions): sin x - sin 3x + sin 5x = 0 ¦Ð ¡Ü x ¡Ü ¦Ð ---------------- Thankyou. I tried find the solutions on my graphics calculator but however, the question is to find the EXACT solution(s) for the equation so I guess it will

    asked by sqleung on February 28, 2008
  31. CALCULUS

    If cos(t)=–7/9, find the values of the following trigonometric functions. Note: Give exact answers, do not use decimal numbers. The answer should be a fraction or an arithmetic expression. a) cos (2t) b) sin (2t) c) cos(1/2) d) sin (1/2) i don't even

    asked by Stumped Student on September 23, 2007
  32. Precalculus

    Use one of the identities cos(t + 2πk) = cos t or sin(t + 2πk) = sin t to evaluate each expression. (Enter your answers in exact form.) (a) sin(19π/4) (b) sin(−19π/4) (c) cos(11π) (d) cos(53π/4) (e) tan(−3π/4) (f) cos(π/4) (g) sec(π/6+ 2π)

    asked by Kaleen on March 11, 2012
  33. Trigonometry

    Solve the equation for solutions in the interval 0

    asked by Renee on March 7, 2016
  34. Mathematics - Trigonometric Identities

    Let y represent theta Prove: 1 + 1/tan^2y = 1/sin^2y My Answer: LS: = 1 + 1/tan^2y = (sin^2y + cos^2y) + 1 /(sin^2y/cos^2y) = (sin^2y + cos^2y) + 1 x (cos^2y/sin^2y) = (sin^2y + cos^2y) + (sin^2y + cos^2y) (cos^2y/sin^2y) = (sin^2y + cos^2y) + (sin^2y +

    asked by Anonymous on November 8, 2007
  35. Math Help

    Hi! Can someone help check this for me and see if I'm doing it right? Thanks!! :) Directions: Use the Half-Angle formulas to determine the exact value of sin(pi/12). Here's what I have: π/12 = ( 180° ) / 12 = 15°. = sin ( π/12 ) = sin 15° = sin ( 45°

    asked by Mimi on February 3, 2015
  36. Trig

    Given: sin x = 4/5, 0 < x < π/2 sin y = 5/13, π/2 < y < π Find the exact value of sin(x + y) I presume I'm supposed to use the sum and difference formulas but I'm not sure how to get the exactly value of cos x or cos y

    asked by R on January 4, 2017
  37. URGENT - Trigonometry - Identities and Proofs

    Okay, today, I find myself utterly dumbfounded by these three questions - Write a proof for - 2/(sqrt(3)cos(x) + sin(x))= sec((pi/6)-x) Solve the following equation - 2sin(2x) - 2sin(x) + 2(sqrt(3)cos(x)) - sqrt(3) = 0 Find all solutions (exact) to the

    asked by Veronica on April 2, 2011
  38. Pre-Calc

    I am really struggling with how to do these problems, I posted them a few minutes ago but the answers/work shown was incorrect. 1) a) Use an Addition or Subtraction Formula to write the expression as a trigonometric function of one number. cos 12° cos

    asked by Alyssa on April 14, 2015
  39. Pre Calculus

    Use one of the identities cos(t + 2ðk) = cos t or sin(t + 2ðk) = sin t to evaluate each expression. (Enter your answers in exact form.) (a) sin(17ð/4) (b) sin(−17ð/4) (c) cos(17ð) (d) cos(45ð/4) (e) tan(−3ð/4) (f) cos(7ð/4) (g) sec(ð/6+2ð)

    asked by Stephanie823 on March 11, 2012
  40. Pre Calculus

    Use one of the identities cos(t + 2ðk) = cos t or sin(t + 2ðk) = sin t to evaluate each expression. (Enter your answers in exact form.) (a) sin(17ð/4) (b) sin(−17ð/4) (c) cos(17ð) (d) cos(45ð/4) (e) tan(−3ð/4) (f) cos(7ð/4) (g) sec(ð/6+2ð)

    asked by Stephanie823 on March 11, 2012
  41. Math

    Solve this equation algebraically: (1-sin x)/cos x = cos x/(1+sin x) --- I know the answer is an identity, and when graphed, it looks like cot x. I just don't know how to get there. I tried multiplying each side by its conjugate, but I still feel stuck.

    asked by Momo on October 18, 2009
  42. trig

    suppose that sin(x) + cos(x) = 4/3 a)square this result and find a value for sin(x)cos(x). b)using the result from a) find the exact value of sin^3(x)+cos^3(x). (Hint: Do you recall how to factor x^3 + y^3)

    asked by chris on April 15, 2010
  43. math

    use exact values of the sin,cos and tan of (pi/3) and (pi/6)(which I have found)and the symmetry of the graphs of sin,cos and tan to find the exact values of sin(-pi/6), cos(5pi/3) and tan (4pi/3). I know that sin -(pi/6) = -1/2 and cos (5pi/30 = 1/2 and

    asked by jenny on August 23, 2011
  44. Calculus

    Use a trig identity to combine two functions into one so you can solve for x. (The solution should be valid for any value of t). 3cos(t) + 3*sqrt(3)*sin(t)=6cos(t-x) I know that 6 cos(t-x) can be 6(cos(t)cosx(x)+sin(t)sin(x)) I don't know where to go from

    asked by Lisa on January 15, 2013
  45. Trig

    Given: cos u = 3/5; 0 < u < pi/2 cos v = 5/13; 3pi/2 < v < 2pi Find: sin (v + u) cos (v - u) tan (v + u) First compute or list the cosine and sine of both u and v. Then use the combination rules sin (v + u) = sin u cos v + cos v sin u. cos (v - u) = cos u

    asked by Nan on December 29, 2006
  46. math

    Can anyone help w/ these. 1) Solve the equation in the internal [0deg, 360deg]. a) sin 2x = -sin x b) sin 2T = -1/2 (where T is angle) c) 4 sin^2T = 3 2) Evaluate the expression. sin(arctan 2) 3) Rewrite the following w/o using trigonometric or inverse

    asked by chyrl on December 9, 2006
  47. Trig (math)

    1.) Write the complex number in trigonometric form r(cos theta + i sin theta) with theta in the interval [0°, 360°). 9 sqrt 3 + 9i 2.) Find the product. Write the product in rectangular form, using exact values. [4 cis 30°] [5 cis 120°] 3.) [4(cos

    asked by Anonymous on December 8, 2014
  48. Math Answer Check

    1. Find the exact value of the expression. cos pi/16 * cos 3pi/16 - sin pi/16 * sin 3pi/16 My ans: sqrt2/2 2. Find the exact value of the sin of the angle. 17pi/12 = 7pi/6 + pi/4 My ans: (sqrt2 - sqrt6)/4

    asked by Anonymous on October 25, 2015
  49. math

    Eliminate the parameter (What does that mean?) and write a rectangular equation for (could it be [t^2 + 3][2t]?) x= t^2 + 3 y = 2t Without a calculator (how can I do that?), determine the exact value of each expression. cos(Sin^-1 1/2) Sin^-1 (sin 7pi/6)

    asked by Anonymous on August 3, 2007
  50. Alg2/Trig

    Find the exact value of the trigonometric function given that sin u = 5/13 and cos v = -3/5. (Both u and v are in Quadrant II.) Find csc(u-v). First of all, I drew the triangles of u and v. Also, I know the formula of sin(u-v) is sin u * cos v - cos u *

    asked by Vincent on June 5, 2009
  51. Precalculs

    I have no idea how to do these type of problems. -------Problem-------- Solve each equation on the interval 0 less than or equal to theta less than 2 pi 42. SQRT(3) sin theta + cos theta = 1 ---------------------- There is an example prior to the

    asked by Kate on March 1, 2010
  52. Calculus

    Okay so I have a question on my assignment that says: You are given that tan(y) = x. Find sin(y)^2. Express your answer in terms of x. I know its derivatives, and I've tried taking the derivatives of both etc, and got them both to come out as cos(y)^2,

    asked by Tracy on October 21, 2006
  53. pre-cal

    Simplify the given expression........? (2sin2x)(cos6x) sin 2x and cos 6x can be expressed as a series of terms that involve sin x or cos x only, but the end result is not a simplification. sin 2x = 2 sinx cosx cos 6x = 32 cos^6 x -48 cos^4 x + 18 cos^2 x -

    asked by ethan on May 17, 2007
  54. Pre calc

    Given that tanθ = 2 root 10 over 9 and cscθ < 0 , find the exact value of cos(θ − pie over 4) . I solved for the other side and got 11. After this idk what to do I was thinking using cos(a-b)=cos(a)cos(b)-sin(a)sin(b) but idk how to witht the pie/4

    asked by Samantha on April 17, 2017
  55. math

    use exact values of the sin,cos and tan of (pi/3) and (pi/6)(which I have found)and the symmetry of the graphs of sin,cos and tan to find the exact values of sin(-pi/6), cos(5pi/3) and tan (4pi/3). I know that sin -(pi/6) = -1/2 and cos (5pi/30 = 1/2 and

    asked by jenny on August 24, 2011
  56. Calculus

    Please look at my work below: Solve the initial-value problem. y'' + 4y' + 6y = 0 , y(0) = 2 , y'(0) = 4 r^2+4r+6=0, r=(16 +/- Sqrt(4^2-4(1)(6)))/2(1) r=(16 +/- Sqrt(-8)) r=8 +/- Sqrt(2)*i, alpha=8, Beta=Sqrt(2) y(0)=2, e^(8*0)*(c1*cos(0)+c2*sin(0))=c2=2

    asked by COFFEE on July 10, 2007
  57. Trig

    1. Establish the identity: sin(theta+3pi/2)=-cos(theta) 2. Find the exact value of 2(theta) if sin(theta)=5/13 3. Show that: csc2(theta)-cot2(theta)=tan(theta) 4. Find the exact value of tan(cos^-1(square root of 3/2) 5. Approximate the value rounded to

    asked by Brittany on December 7, 2011
  58. Trigonometry

    1.Solve tan^2x + tan x – 1 = 0 for the principal value(s) to two decimal places. 6.Prove that tan y cos^2 y + sin^2y/sin y = cos y + sin y 10.Prove that 1+tanθ/1-tanθ = sec^2θ+2tanθ/1-tan^2θ 17.Prove that sin^2w-cos^2w/tan w sin w + cos w tan w =

    asked by Alonso on January 1, 2013
  59. Pre-Calc

    1) Use an Addition or Subtraction Formula to write the expression as a trigonometric function of one number. cos 12° cos 18° − sin 12° sin 18° And Find its exact value. 2) Use an Addition or Subtraction Formula to write the expression as a

    asked by Alyssa on April 14, 2015
  60. math

    Can you please check my work. A particle is moving with the given data. Find the position of the particle. a(t) = cos(t) + sin(t) s(0) = 2 v(0) = 6 a(t) = cos(t) + sin(t) v(t) = sin(t) - cos(t) + C s(t) = -cos(t) - sin(t) + Cx + D 6 = v(0) = sin(0) -cos(0)

    asked by Kay on June 24, 2011
  61. math

    Determine exact value of cos(cos^-1(19 pi)). is this the cos (a+b)= cos a cos b- sina sin b? or is it something different. When plugging it in the calculator, do we enter it with cos and then the (cos^-1(19 pi)).

    asked by Anonymous on April 15, 2012
  62. math

    Sin theta equals 5/12 in quadrant, find the exact value of cos 2theta. I'm not sure how to solve this question, I need some help.

    asked by alyssa on January 16, 2015
  63. Trigonometry desperate help, clueless girl here

    2. solve cos 2x-3sin x cos 2x=0 for the principal values to two decimal places. 3. solve tan^2 + tan x-1= 0 for the principal values to two decimal places. 4. Prove that tan^2(x) -1 + cos^2(x) = tan^2(x) sin^2 (x). 5.Prove that tan(x) sin(x) + cos(x)=

    asked by Suzy on August 17, 2013
  64. Trig

    Solve each equation for exact solutions over the interval [0,360)where appropriate. Round approximate solutions to the nearest tenth degree. Sin^2Theta=Cos^2Theta+1 My Work: Using double angle Identity I subtract 1 to other side therefore:

    asked by Ronald on April 27, 2016
  65. Trig

    If cosx = 10/19 an pi < x < 2pi, find the exact value of cos x/2 Use the double angle formula. Cos 2Y= sin^2 Y - cos^2Y = 1-2Cos^2 Y. let y= x/2, and 2Y=x

    asked by Ashley on April 14, 2007
  66. math

    Prove that for all real values of a, b, t (theta): (a * cos t + b * sin t)^2

    asked by mathstudent on December 20, 2006
  67. Trigonometry

    Please review and tell me if i did something wrong. Find the following functions correct to five decimal places: a. sin 22degrees 43' b. cos 44degrees 56' c. sin 49degrees 17' d. tan 11degrees 37' e. sin 79degrees 23'30' f. cot 19degrees 0' 25'' g. tan

    asked by Anon on January 1, 2011
  68. Precalculus

    I am trying to submit this homework in but i guess i'm not doing it in exact values because it is not accepting it. I know i'm supposed to be using half angle formulas but maybe the quadrants are messing me up. Please help! Find sin x/2 , cos x/2 , and tan

    asked by J.P. on November 10, 2015
  69. trigonometry HELP pleasE!

    these must be written as a single trig expression, in the form sin ax or cos bx. a)2 sin 4x cos4x b)2 cos^2 3x-1 c)1-2 sin^2 4x I need to learn this!! if you can show me the steps and solve it so I can learn I'd be grateful!!! 1) apply the formula for sin

    asked by jim on November 1, 2006
  70. Trigonometry

    I need help with I just can't seem to get anywhere. this is as far as I have got: Solve for b arcsin(b)+ 2arctan(b)=pi arcsin(b)=pi-2arctan(b) b=sin(pi-2arctan(b)) Sub in Sin difference identity let 2U=(2arctan(b)) sin(a-b)=sinacosb-cosasinb

    asked by Jen on July 27, 2007
  71. Trig

    Find sin(s+t) and (s-t) if cos(s)= 1/5 and sin(t) = 3/5 and s and t are in quadrant 1. =Sin(s)cos(t) + Cos(s)Sin(t) =Sin(1/5)Cos(3/5) + Cos(-1/5)Sin(3/5) = 0.389418 Sin(s-t) =sin(s)cos(t) - cos(s)sin(t) =sin(-3/5)cos(1/5) - cos(1/5)sin(3/5) =Sin-3/5

    asked by Sally on May 7, 2015
  72. Pre Cal

    Let P be the point on the unit circle U that corresponds to t. Find the coordinates of P and the exact values of the trigonometric functions of t, whenever possible. (If there is no solution, enter NO SOLUTION.) 4ð = ( , ) sin(4ð) = cos(4ð) = tan(4ð) =

    asked by Karmen on February 9, 2010
  73. trig

    it says to verify the following identity, working only on one side: cotx+tanx=cscx*secx Work the left side. cot x + tan x = cos x/sin x + sin x/cos x = (cos^2 x +sin^2x)/(sin x cos x) = 1/(sin x cos x) = 1/sin x * 1/cos x You're almost there. thanks so

    asked by Devon on May 8, 2007
  74. trigonometry (please double check this)

    Solve the following trig equations. give all the positive values of the angle between 0 degrees and 360 degrees that will satisfy each. give any approximate value to the nearest minute only. 1. sin2Į = (sqrt 3)/2 2. sin^2Į = cos^2Į + 1/2 3. sin 2x

    asked by anon on March 3, 2011
  75. Trig(3 all with work)

    1)Find the exact value of cos 105 by using a half-angle formula. A)sqrt 2 - sqrt 3 /2 B)-sqrt 2 - sqrt 3 /2 C)-sqrt 2 + sqrt 3 /2 D)sqrt 2 + sqrt 3 /2 cos 105 cos 105 = cos 210/2 sqrt 1 + 210/2 sqrt 1 + sqrt 3/2 /2 sqrt 2 + sqrt 3/2 which is D 2)Find the

    asked by Jon on February 15, 2008
  76. Math (Trigonometry [Polar Form])

    Let z be a complex number such that z = 2(cos 8∘ + i cos 82∘).Then z^5 can be expressed as r(sin α∘+ i cos α∘), where r is a real number and 0 ≤ α ≤ 90. What is the value of r+α? Hint to solve: Example Question: Let z be a complex number

    asked by Shin on June 22, 2013
  77. Trig Help!

    Question: Trying to find cos π/12, if cos π/6 = square root 3 over 2, how to find cos π/12 using DOUBLE angle formula? This is what I got so far.. cos 2(π/6) = cos (π/6 + π/6) = (cos π/6)(cos π/6) - (sin π/6)(sin π/6) = cos^2 π/6 - sin^2 π/6 Is

    asked by Anonymous on April 28, 2012
  78. Pre Cal

    Let P be the point on the unit circle U that corresponds to t. Find the coordinates of P and the exact values of the trigonometric functions of t, whenever possible. (If there is no solution, enter NO SOLUTION.) 9pi/4 Looking for sin, cos, tan,cot, csc,

    asked by Karmen on February 10, 2010
  79. Math/Calculus

    Please check my work and correct any errors/point out any errors. Thanks. Solve the initial-value problem using the method of undetermined coefficients. y''-4y=e^xcos(x), y(0)=1, y'(0)=2 r^2-4=0, r1=2, r2=-2 yc(x)=c1*e^2x+c2*e^-2x

    asked by COFFEE on July 13, 2007
  80. calculus

    Find the points on the curve y= (cos x)/(2 + sin x) at which the tangent is horizontal. I am not sure, but would I find the derivative first: y'= [(2 + sin x)(-sin x) - (cos x)(cos x)]/(2 + sin x)^2 But then I don't know what to do or if that is even

    asked by CMM on October 24, 2010
  81. Please help!!!)

    If sin(x) = /45 and cos(y) = 5/13 with both x and y terminating in quadrant 1 find the exact value of cos(x-y) cos(4/5 - 5/13) Is this what I would do?

    asked by Bryan on March 19, 2010
  82. math

    If sin(x) = /45 and cos(y) = 5/13 with both x and y terminating in quadrant 1 find the exact value of cos(x-y) cos(4/5 - 5/13) Is this what I would do?

    asked by Bryan on March 19, 2010
  83. Math

    If sin(x) = /45 and cos(y) = 5/13 with both x and y terminating in quadrant 1 find the exact value of cos(x-y) cos(4/5 - 5/13) Is this what I would do?

    asked by Bryan on March 19, 2010
  84. Mathematics - Trigonometric Identities - Reiny

    Mathematics - Trigonometric Identities - Reiny, Friday, November 9, 2007 at 10:30pm (sinx - 1 -cos^2x) (sinx + 1 - cos^2x) should have been (sinx - 1 + cos^2x) (sinx + 1 - cos^2x) and then the next line should be sin^2x + sinx - cos^2xsinx - sinx - 1 +

    asked by Anonymous on November 10, 2007
  85. AP Calculus

    Find the velocity, v(t), for an object moving along the x-axis if the acceleration, a(t), is a(t) = cos(t) - sin(t) and v(0) = 3 v(t) = sin(t) + cos(t) + 3 v(t) = sin(t) + cos(t) + 2 v(t) = sin(t) - cos(t) + 3 v(t) = sin(t) - cos(t) + 4

    asked by Will on June 19, 2018
  86. Math

    sin theta = 8/17 and theta is in the second quadrant. Find sin(2theta),cos(2theta),tan(2theta) exactly sin(2theta) cos(2theta) tan(2theta) sin(2theta) would it be 2 x (8/17) cos(2theta) would be 2 x (15/17) tan(2theta) would be 2 x (8/17 divided by 15/17)

    asked by Sally on November 14, 2014
  87. math

    Find the exact value of the expression. cos(π/16)cos(3π/16) − sin(π/16) sin(3π/16)

    asked by Stella on June 10, 2018
  88. Algebra II

    1) Find the exact value of cos 105 degrees by using a half-angle formula. 2)Find the solution of sin 2theta = cos theta if 0 degrees

    asked by Lucy on April 19, 2008
  89. calc

    find the area between the x-axis and the graph of the given function over the given interval: y = sqrt(9-x^2) over [-3,3] you need to do integration from -3 to 3. First you find the anti-derivative when you find the anti-derivative you plug in -3 to the

    asked by mikayla on April 19, 2007
  90. pre-calc

    Solve: cos(2x-180) - sin(x-90)=0 my work: cos2xcos180 + sin2xsin180= sinxcos90 - sin90cosx -cos2x - sin2x= cosx -cos^2x + sin^2x -2sinxcosx=cosx I'm stuck here. I tried subtracting cosx from both sides and making sin^2x into 1- cos^2x, but I still can't

    asked by Jess on February 7, 2007
  91. Pre-Calc

    How do I solve this? My work has led me to a dead end. tan(45-x) + cot(45-x) =4 my work: (tan45 - tanx)/(1+ tan45tanx) + (cot45 - cotx)/(1 + cot45cotx) = 4 (1-tanx)/(1+tanx) + (1-cotx)/(1+cotx) = 4 Then I found a common denominator, giving me this:

    asked by Jess on February 7, 2007
  92. Trigonometry

    Find the general solution of the following equation. sin (5x) = cos (3x) sin (6x) sin (x) = cos (3x) cos (4x) Thanks for your help :)

    asked by Tommy on July 22, 2008
  93. trigonometry

    In questions 2A, 2B, and 2C below, find the exact values using the given information: sin α = 1/6 with α between 0 and π/2 sin β = 3/5 with β between π/2 and π 2A. Find cos (α + β) 2B. Find tan (2β) 2C. Find sin (β/2)

    asked by ashley on March 6, 2016
  94. math

    find all solutions in the interval [0,2 pi) sin(x+(3.14/3) + sin(x- 3.14/3) =1 sin^4 x cos^2 x Since sin (a+b) = sina cosb + cosb sina and sin (a-b) = sina cosb - cosb sina, the first problem can be written 2 sin x cos (pi/3)= sin x The solution to sin x =

    asked by lauren on March 22, 2007
  95. Calculus - Second Order Differential Equations

    Posted by COFFEE on Monday, July 9, 2007 at 9:10pm. download mp3 free instrumental remix Solve the initial-value problem. y'' + 4y' + 6y = 0 , y(0) = 2 , y'(0) = 4 r^2+4r+6=0, r=(16 +/- Sqrt(4^2-4(1)(6)))/2(1) r=(16 +/- Sqrt(-8)) r=8 +/- Sqrt(2)*i,

    asked by COFFEE on July 10, 2007
  96. math;)

    Show that sin(x+pi)=-sinx. So far, I used the sum formula for sin which is sin(a+b)=sin a cos b+cos a sin b. sin(x+pi)=sin x cos pi+cos x sin pi I think I am supposed to do this next, but I am not sure. sin(x+pi)=sin x cos x+sin pi cos pi If that is right

    asked by girly girl on April 27, 2018
  97. Trig

    Solve in terms of sine and cosine: sec(x) csc(x)- sec(x) sin(x) so far I have: 1/cos(x) 1/sin(x) - 1/cos(x) sin(x) I am not sure where to go to from there. The book says the answer is cot(x) or cos(x)/sin(x) Thank you in advance.

    asked by Dennis on April 9, 2008
  98. Trig

    If angle A is 45 degrees and angle B is 60 degrees. Find sin(A)cos(B), find cos(A)sin(B), find sin(A)sin(B), and find cos(A)cos(B) The choises for the first are: A. 1/2[sin(105)+sin(345)] B. 1/2[sin(105)-sin(345)] C. 1/2[sin(345)+cos(105)] D.

    asked by Sade on October 8, 2016
  99. trigonometry

    5. If cot 2θ = 5/12 with 0 ≤ 2θ ≤ π , find cosθ, sinθ, and tanθ 8. Find the exact value of sin2a if cosa = 4/5(a in Quadrant I) 13. Find the exact value of tan2 if sinB = 5/13 (B in quadrant II) 14. Solve sin 2x + sin x = 0 for 0 ≤ x ≤

    asked by Alonso on December 18, 2012
  100. trig

    Graph one complete cycle of y + cos x cos pi over6 + sin x sin pi/6 by first rewriting the right side in the form cos(A-B)

    asked by Rick on February 28, 2008