If cos(t)=(-7/8) where pi

4,795 questions, page 9
  1. Trigg

    How do I find a rectangular-coordinate equation for the curve by elimination the parameter? x=2 sin t, y= 4 cos t so far I have x= r cos(theta) and y= r sin (theta) but, it's the opposite. please help.

    asked by Jenny on March 17, 2014
  2. MathsSs triG

    Consider sin(x-360)sin(90-x)tan(-x)/cos(90+x) 1.A.SIMPLIFY sin(x-360)sin(90-x)tan(-x)/cos(90+x) to a single trigonometric ratio B.hence or otherwise without using a calculator,solve for X if 0

    asked by katlego ratsoma on October 3, 2013
  3. Calculus

    What is the derivative of k(x)=sin x cos x? A. -sin x cos x B. -2 sin x cos x C. 2 cos^2x-1 D. sin^2x - cos^2x

    asked by hhhhh on January 12, 2017
  4. physics

    a 17.0kg crate is to be pulled a distance of 20.0m requiring 1210J of work being done. If the job is done by attaching a rope and pulling with a force of 75.0 N, at what angle is the rope held? W=Fd(cos) 1210J=(170)(20m)(cos)

    asked by Anonymous on February 24, 2010
  5. MATH

    Differential equations, initial value problem. The general equation of motion is: mx"+Bx'+kx=f(t), where the independent variable is t, and the displacement x is the dependent variable. In this case, external force f(t)=0, so mx"+Bx'+kx=0 substitute

    asked by Anonymous on March 16, 2011
  6. Trigonometry

    Hi. I am reposting this. Can you verify. Thanks. (cosθ) / (sinθ – 1) + (cosθ)/ (1 + sinθ) = -2tanθ (1 / cos^2θ) – (2) (1/cos^2θ) (sinθ / cosθ) + (sin^2θ / cos^2θ) = (1 - sinθ) / (1 + sinθ)

    asked by Ashley Kate on March 1, 2014
  7. Calculus

    (This problem uses a TI-89 calculator) Find the largest and smallest values of the following function on their given intervals: y=(cos x)^x [-1.5, 4.75] This is what I put in the calculator (home screen): fMin((cos(x))^x,x I -1.5 < x < 4.75 (I = "with"

    asked by Anonymous on June 8, 2009
  8. Calculus (repost)

    This problem uses a TI-89 calculator) Find the largest and smallest values of the following function on their given intervals: y=(cos x)^x [-1.5, 4.75] This is what I put in the calculator (home screen): fMin((cos(x))^x,x I -1.5 < x < 4.75 (I = "with"

    asked by Anonymous on June 8, 2009
  9. Pre Cal.

    Express 5sqrt(3) - 5i in polar form. A: 10(cos(11pi/6) + i sin(11pi/6)) Express 4(cos(3pi/4) + i sin(3pi/4)) in rectangular form. A: -2sqrt(2) + 2sqrt(2i Write 2x+y=5 in polar form. A: sqrt(5)= r cos (theta-27degrees) Are these correct?

    asked by Jeremy on August 15, 2009
  10. Trig

    Find all solutions w between 0 and 360, inclusive: (a) cosw = cos(−340) (b) cosw = sin20 (c) sinw = cos(−10) (d) sinw < − 1 2 (e) 1 < tanw

    asked by Sally K on April 11, 2010
  11. Trig

    Find all solutions w between 0 and 360, inclusive: (a) cosw = cos(−340) (b) cosw = sin 20 (c) sinw = cos(−10) (d) sin w < − 1/2 (e) 1 < tanw

    asked by sally on April 12, 2010
  12. maths

    Find all possible solutions in the range 0°≤ x ≤ 180° of the following equations: (a) cos x = sqrt(2) / 2 (b) tan x = sqrt(3) / 3 (c) sin x = sin60° (d) cos x = -1/2 (e) sin x = -1/2

    asked by Steven on November 18, 2016
  13. MATHS

    Find all possible solutions in the range 0°≤ x ≤ 180° of the following equations: (a) cos x = sqrt(2) / 2 (b) tan x = sqrt(3) / 3 (c) sin x = sin60° (d) cos x = -1/2 (e) sin x = -1/2

    asked by Joshua on November 21, 2016
  14. Quantum Physics

    I.Provide a unitary that maps |+> to |1> and |-> to |0> . Enter 0 in all boxes if no such unitary exists. (In this case, you have to enter 0 explicitly. Blanks are not accepted.) a b c d II.Provide a unitary that maps cos (30) |0> + sin (30) |1> to

    asked by Bel on March 15, 2013
  15. Math - Trig - Double Angles

    Prove: cos4x = 8cos^4x - 8cos^2x + 1 My Attempt: RS: = 4cos^2x (2cos^2x - 1) + 1 = 4 cos^2x (cos2x) + 1 LS: = cos2(2x) = 2cos^2(2x) - 1 = (cos^2(2)) - cos^2(2x)) - 1 ----- Prove: 8cos^4x = cos4x + 4cos2x + 3 My Attempt: RS: = cos2(2x) + 4cos(2x) + 3 =

    asked by Anonymous on November 17, 2007
  16. Plane Trigonometry

    tan A=-4/5;A in Quadrant 2 and cos B=-5/13: B in Quadrant 3. What is the exact value of the expression cos(A+B)?

    asked by Math on November 2, 2016
  17. Pre-Calculus

    Given cos A = -3/5, π

    asked by Anonymous on October 24, 2018
  18. math help trigonometry

    Prove the following identity tan x cos x/sin x=1/sin x cos x

    asked by lewis on June 10, 2015
  19. math

    Find the imaginary part of (cos(12) + i sin(12) + cos(48) + i sin(48))^6.

    asked by Katie on May 28, 2016
  20. Pre calc

    Someone please help me prove these A) cos^4x-sin^4x=cos2x B)tanx=sin^2x/1+cos^2x Please and Thank you

    asked by Bethany on April 13, 2017
  21. Pre calc

    Someone please help me prove these A) cos^4x-sin^4x=cos2x B)tanx=sin^2x/1+cos^2x Please and Thank you

    asked by Samantha on April 13, 2017
  22. Math

    Find all values of x in the interval [0, 2 pi] that satisfy 2 cos x-1 = 0. cos x = 1/2 x = 60 How do I find the other value of x?

    asked by Raj on September 25, 2007
  23. 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
  24. precalculus

    Solve the equation cos(2x)cos(x)+sin(2x)+sin(x)=1 for all values of x.

    asked by marie darling on April 14, 2013
  25. Trig

    Verify the Identity (sin m +sin n)/ (cos m + cos n) = tan(m + n/2)

    asked by Steve on October 24, 2009
  26. math

    how do I solve this? (cos ө+1)/ (cos ө - 1) The answer is supposed to be: (1 + sec ө)/ (1- sec ө)

    asked by kayla on February 8, 2009
  27. Precalc

    Prove or disprove the following identity. cos(-x) - sin(-x) = cos(x) + sin(x)

    asked by George on November 13, 2012
  28. Math

    Match the trigonometric expression: cos^2 [(pi/2) - x] / cos x Does csc x match with this?

    asked by Hannah on March 5, 2010
  29. Trigonometry

    What are these things called: -cos x = cos -x What are the rules to these trig rules? Thanks

    asked by Trigonometry on January 22, 2012
  30. mth, trig

    Given cos a=-7/25 in quadrant II , and sin b=-12/13, in quadrant IV , find cos(a+b) and sin2a

    asked by shay on April 18, 2012
  31. Trig

    Prove the identity: (sin⁡(2x-y)+sin⁡y)/(cos⁡(2x-y)+cos⁡y )=tan⁡x

    asked by Alexa on July 30, 2015
  32. math

    how to find the period of y = cos(6x)from your graph. what is the period of y=cos(6x) in radians?

    asked by subash on April 8, 2010
  33. Precalculus

    Find the exact value of: Cos(inverse tan 4/3 + inverse cos 5/13)

    asked by Thomas on April 21, 2014
  34. math

    how to find the period of y = cos(6x)from your graph. what is the period of y=cos(6x) in radians?

    asked by subash on April 8, 2010
  35. Trigonometry

    Prove that sin(n+1)A-sin(n-1)A/cos(n+1)A+2cosnA+cos(n-1)A = tanA/2

    asked by Kewal on January 5, 2012
  36. math

    how do you simplify cos(A+B)*cos B=sin(A+B)*sin B can you show me the steps? thank you very much!!!

    asked by candybar on February 9, 2011
  37. Maths

    (Cos/1+cosec) + (sin/ 1+cot ) = sin + cos prove that

    asked by Sanjay on August 19, 2017
  38. maths trigo

    prove that sin(n+1)A-sin(n-1)A/cos(n+1)A+2cos(nA)+cos(n-1)A=tanA/2

    asked by ankita on September 30, 2012
  39. Algebra II Part 2

    Use an angle sum identity to verify the identity cos 2 0=2 cos 0-1

    asked by Karen on May 18, 2013
  40. pre calc

    sin 20 pi cos 9 pi cos 13pi/2 sin(-17 pi0 are all of these undefined?

    asked by jim on January 2, 2012
  41. trigo

    Obtain an identity for the first function value in terms of the second function value. cos 3x ; cos x

    asked by rai zan on September 28, 2014
  42. trig

    suppose sin(x)=5/6, and x is in the first quadrant. Determine cos(x), sin(2x), and cos(2x).

    asked by jj reddick on October 24, 2010
  43. physics

    A dive bomber has a velocity of 290 m/s at an angle θ below the horizontal. When the altitude of the aircraft is 2.15 km, it releases a bomb, which subsequently hits a target on the ground. The magnitude of the displacement from the point of release of

    asked by Spice on October 25, 2015
  44. Algebra II

    Multiple Choice Which expression is NOT equivalent to 1? (theta) means 0 with dash in it. A.)sin^2 (theta)+cot^2 (theta) sin^2 (theta) B.)(sin^(theta))/(1-cos(theta))-cos(theta) C,)sec^2 (theta)+ tan^2 (theta) D.)(cot^2(theta) sin^2 (theta))/(cos^2(theta))

    asked by HotMath on June 9, 2011
  45. Calculus

    Determine an upper/lower estimate for the area under the curve f(x) = cos x between x = 0 and x = pi/2 . Show how you arrive at this estimate. This is the question that my teacher wanted us to answer and I'm not sure how to even start the process. Should I

    asked by Mia on October 29, 2016
  46. Calculus

    Find all points on the graph of the function f(x) = 2 cos(x) + (cos(x))2 at which the tangent line is horizontal. Consider the domain x = [0,2π). I have pi/2 and 3pi/2 for x values. But when I plug them I get zero. Is this correct as y values or am I

    asked by Calculus on January 11, 2016
  47. 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
  48. trigonometry

    I need help in understanding how to identify which identity to use. using this question as an example. Show that tan theta (sin theta+cot theta cos theata)all over cos theta = sec^2 theta. Please explain.

    asked by lindsay on May 4, 2012
  49. precalculus

    Find the tan(x), the sin (x + pi) if it is known that cos (x)=.6 and that (3pi)/2 less than x less than 2pi. Find the sine (2x), the tan (2x), and the cos (x/2) if it is known that cos (x)=.6 and that (3pi)/2 less than x less than 2pi.

    asked by marie darling on April 10, 2013
  50. physics

    A block accelerates at 3.3 m/s^2 down a plane inclined at an angle of 26 degrees.Find micro(k) between the block and the inclined plane. The acceleration of gravity is 9.81 m/s^2. This is my work but i am not sure if it is correct: sum of forces on x axis=

    asked by alexa on July 14, 2011
  51. maths

    expand each of the following using the compound angle formulae a. cos(A - B) b. sin(alpher + alpher) c. cos(alpher + 70°)

    asked by herMajesty on April 27, 2016
  52. Math Please Help

    Eliminate the parameter and sketch the curve. x=cos(theta) , y=cos^2(theta) + 8cos(theta)

    asked by Ally on May 20, 2015
  53. trig

    Given sin a = 15/17 with a in Quadrant I and cos beta = 4/5 with beta in QuandrantIV, find the exact value of cos(a+beta)

    asked by MIK on May 17, 2012
  54. Math

    Prove the identities 1. cos3Ɵ + cos Ɵ = 4cos^Ɵ - 2 cos Ɵ 2. sin (A+B)sin (A-B)=cos2B + sin^2 A-1

    asked by Anonymous on October 25, 2012
  55. Math

    Guys please help me with this Trigonometry question based on De Moivre's theorem. Q: Find ¦È such that 0¡Ü¦È¡Ü360. cos7¦È + cos3¦È = cos5¦È I attempted to solve it with limited knowledge but I kind of doubt my answer. Anyway, this is how I

    asked by Nye on October 16, 2016
  56. Calculus

    Consider the curve below. x = (cos(t))^2 y = cos(t) 0 ≤ t ≤ 6π (a) Find the distance traveled by a particle with position (x, y) as t varies in the given time interval. (b) What is the length of the curve? I have no idea on how to evaluate this

    asked by Jed on December 12, 2015
  57. pre-calc

    simplfy the expression by double angle formula or a half angle formula. cos^2(x/2)-sin^2(x/2) 2sin(x/2)cos(x/2)

    asked by Amanda on April 22, 2012
  58. trigonometry

    1) Perform the operation and leave the result in trig. form. [3/4(cos pi/3 + i sin pi/3)][4(cos 3pi/4 + i sin 3pi/4)] Thanks

    asked by mikey on December 3, 2012
  59. Math

    Write the first trigonometric function in terms of the second for θ in the given quadrant. tan(θ), cos(θ); θ in Quadrant IV I believe to start this is 1/cos^2*theta. Am I write? If not, can you please help me?!

    asked by Jennifer on April 14, 2016
  60. Calculus

    Integrate 1/sinx dx using the identity sinx=2(sin(x/2)cos(x/2)). I rewrote the integral to 1/2 ∫ 1/(sin(x/2)cos(x/2))dx, but I don't know how to continue. Thanks for the help.

    asked by Andre on January 11, 2016
  61. Trigonometry

    Use the power-reducing formulas to rewrite the expression in terms of the first power of the cosine. [#1.] (sin^4x)(cos^4x) [#2.] (sin^4x)(cos^2x)

    asked by Tom on November 29, 2008
  62. maths

    Angle a lies in the second quadran and angle b lies in the third quadrant such that cos a = -3/5 and tan b = 24/7. Determine an exact value for cos (a+b), sin(a-b)

    asked by sayan on April 11, 2012
  63. Math

    Calculate the integral ∫-2e^(Sin(x)) Cos(x) dx , u = Sin(x) Just having a slight hard time at finding du to solve the integral du: Cos(x) dx

    asked by B-c on October 2, 2018
  64. maths

    Prove the following trigonometric identities (i)(1+cotx)^2 +(1-cotx)^2=2cosec^2x (ii)cos(270degrees+theta)/cos(360degrees -theta)

    asked by tembo on February 27, 2012
  65. Math

    Find the quotient of the following expression: 7(cos 5pi/6 +isin 5pi/6) / -2(cos pi/2 +isin pi/2) I got -7/4+ 7 square root 3/4 i. Is this correct?

    asked by Anonymous on January 9, 2015
  66. Trig

    How do I write cos(11x)cos(x)+sin(11x)sin(x) as a single trigonometric function? Please show steps.

    asked by Anonymous on April 3, 2016
  67. Spherical Trigonometery

    I am trying to apply the formula cos c = cos a x cos b + sin a x sin b x cos C to find the length of c in my spherical triangle. I am working with 2 examples in a book in which the answers are given. In the first example all the sines & cosines calculated

    asked by Mike on January 15, 2008
  68. trig

    2. Determine the amplitude of: y= cos x 3. Determine the domain of: y= 4 sin x 4. Determine the range of: y= - sin x 5. Determine the period of: y= 3 sin ðx 6. Determine the phase shift of: y= 3 cos (2x -1) 7. Solve the following equation for indicated

    asked by Bernice on December 17, 2009
  69. Instantaneous rate of change

    Please help.. Joe is investigating the rate of change of the function y=cos x on the interval xE[0,2π]. He notices that the graph of y=cos x passes through the x-axis at 45°. He also determines the instantaneous rate of change at x = 0, π, and 2π by

    asked by Kjd on May 23, 2012
  70. Trig

    Half angle identities Find exact values of a) cos 1/2 b) sin 1/2 c) tan 1/2 based on: cos = 1/5 greater than 270 deg less than 360 deg. I get a) - rt 3/5 b) rt24/5 and c) does not work out at all .... Help please.. book says for answers a)-rt15/5 b) rt10/5

    asked by Don on January 1, 2012
  71. Pre Calculus.

    Can someone check my answers please!!! Simplify (tan ^2 theta csc^2 theta-1)/(tan^2 theta). My answer: 1 Simplify ((cos x)/(sec x-1)) + ((cos x) /(sec x +1) My answer: 2cot^2 x Find a numerical value of one trigonometric function of x if (tan x/cot x )–

    asked by Austin on April 21, 2009
  72. Math

    Derive this identity from the sum and difference formulas for cosine: sinasinb=1/2[cos(a-b)cos(a+b)] Start with the right-hand side since it is more complex. Calculations: _____ _____ _____ Reason: _____ _____ _____

    asked by Don'tknowtrig on May 28, 2018
  73. Trig

    assume A= alpha using complementary rule how do I solve for alpha? cos(2A+40) =sin(3A-60) I don't understand how to start the question. What are the steps in solving for alpha. Do i get cos to equal sin somehow?

    asked by ALISON on September 1, 2011
  74. Calculus

    Use a graphing utility to graph the polar equation shown below. r = cos 5Θ + n cos Θ, 0 ≤ Θ ≤ π For the integers n = -5 to n = 5. As you graph these equations, you should see the graph change shape from a heart to a bell. I'm sorry. I'm having

    asked by Iris on December 6, 2016
  75. Calculus

    How would I find the antiderivative of this equation? S 0 to pi/3 (1-secxtans)dx This should be one that you should just recognize from your study of trig derivatives. Isn't the derivative of sec x, or (cos x)^-1 -(cos x)^-2(-sin x) ?? and isn't that

    asked by Anonymous on May 16, 2007
  76. Extrema-Check my work please?

    Find and classify the relative maxima and minima of f(x) if f(x)= defint a=0 b=x function= t^2-4/(1+cos(x)^2) dt x^2-4/(1+cos(x)^2)= 0 x^2-4=0 x^2=4 x= +/- 2 So I got relative maximum as -2 and 2. And relative minimum as zero. However, when I graph it on

    asked by Eric on May 17, 2013
  77. pre cal

    Suppose cos(u)=3/5 and sin(u) is positive. sin(u)= sin(u−π)= cos(u−π)= sin(u−π/2)= cos(u−π/2)=

    asked by tor on August 2, 2016
  78. math

    Evaluate. 1. sin^-1(-1/2) 2. cos^-1[(-root 3)/2] 3. arctan[(root3)/3] 4. cos(arccos2/3) 5. arcsin(sin 2pi) 6. sin(arccos 1) I got these values as my answers: 1. -pi/6 2. 5pi/6 3. pi/6 4. 2/3 5. 2pi 6. 0 Can someone please tell me if they are right? thank

    asked by anonymous on January 7, 2010
  79. Calculus

    f(x) = 6(cos(x))^2 - 12sin(x) 0 ¡Ü x ¡Ü 2(PI) I have to find where the interval is increasing, decreasing, local mins and maxs, inflection points, and concave up and down. I understand how to do these type of problems. I am just getting messed up with

    asked by Calculus on October 11, 2010
  80. Algebra 2

    Simplify the trigonometric expression. sin^2 theta / 1-cos theta A. 1+cos theta B. sin theta C. 1-sin theta / cos theta D. 1+sin theta / cos theta

    asked by Caleb on May 25, 2014
  81. Math/trig

    Solve the equation in the given Domain: 1-cos theta/ sin theta = sqr3, 0degrees

    asked by Dre on November 13, 2011
  82. Pre calc

    Find sin(2x), cos(2x), and tan(2x) from the given information. sin(x) = 5/13, x in Quadrant I sin(2x)? cos(2x)? tan(2x)? I honeslty just need one good example of how to do these please show all work and finalize answer

    asked by Armani on April 13, 2017
  83. physics

    A 56-kg rollerblader skates across a skating rink floor. The graph below shows the net external force component F cos è along the displacement as a function of the magnitude of the displacement d. Determine the Following: (a) work done by the net force

    asked by John on October 12, 2015
  84. Math

    Solve each equation for all real values of x. 7.) 3 cos 2x - 5 cos x = 1 8.) 2 sin^2 x-5 sin x + 2 = 0 9.)3 sec^2 - 4 = 0 10.) tan x (tan x-1) = 0

    asked by Maurice on March 22, 2012
  85. math

    Without using a calculator, choose (a) the larger of cos 40 and cos 50; (b) the larger of sin 40 and sin 50. Be prepared to explain your reasoning.

    asked by Grace on February 8, 2017
  86. math-precalculus

    sin(6x)cos(11x)+cos(6x)sin(11x)=-0.1 solve for all solutions and provide steps so I can follow.. thank you

    asked by Anonymous on May 24, 2017
  87. Pre-Calc

    Evaluate the two trigonometric functions using its period as an aid. 1. cos (9pi/2) = ? Ans: 0 2. cos (-9pi/2) = ? Ans: 0

    asked by Anonymous on September 9, 2015
  88. Math!!!

    angle x is in the second quadrant and angel y is in the first quadrant and angle y is in the first quardrant such that sin x=5/13 and cos y = 3/5. Determine and exact value for cos x.

    asked by Anonymous on November 8, 2010
  89. math

    show that : cos(360*+x)-tan(180*-x)sin(360*-2x)cos(-x) divided by sin(90*+x)=cos2x

    asked by Ben on April 16, 2015
  90. [Calculus] U-substitution for Integrals

    Integral of cos(x)*a^sin(x) + C dx = Integral of cos(x)*sin(x)^a + C dx = Let a be a fixed positive number. I'm clueless is to how to solve for a...

    asked by Ian on February 23, 2015
  91. Math/calculus

    Prove Sin 8theta -sin 10theta= cot 9theta (cos 10theta - cos 8 theta)

    asked by Jessica on November 14, 2017
  92. Trigonometry

    Need help solving problems using the Trigonometric Identities: 8cos^4 thet=cos4theta+4cos2theta+3 I am a bit unsure how to solve it. I am aware that the first step I must take is to simplify the problem and then use the Product to Sum formula Nasty one!

    asked by sierra on April 23, 2007
  93. Trigonometry

    What is sin(cos^-1 a) when 0 < cos^-1 a < 90

    asked by Rachel on December 1, 2012
  94. Math

    Simplify cos(x+y)-cos(x-y)

    asked by Jenny on December 13, 2016
  95. Trig


    asked by Hannah on May 6, 2013
  96. Algebra 2/ Trigonometry

    If cos y = -4/5 when 90°≤ y ≤ 180° what is the value of cos 2y?

    asked by Moe on April 27, 2013
  97. trig

    simplify cos(30+x)+cos(30-x)

    asked by Anonymous on December 11, 2010
  98. trig

    Solve the following for x, where 0 < x < 2 pi. 2 cos^2 x + cos x = 1

    asked by Sandy on March 8, 2010
  99. Math

    3 cos (ωt + 2) + 4 sin (ωt + 1) as A cos (ωt + φ) . A = ? φ= ?

    asked by jiya on February 2, 2016
  100. maths

    cos(a+b)=m(cos(a-b) then tan a=?

    asked by pooja on April 30, 2011