# find the exact value of cos 300 degrees

105,057 questions
1. ## math

Find the exact value of cos 300 degrees. thanks guys cos 300 = 1/2 = 0.500 how do you know? I am supposed to show my work. You ought to know the rule on 30-60-90 triangles. If the hyp is 2, the shorter side is 1, and the longer side is sqrt3. what does

asked by Bill on June 2, 2007
2. ## Math

Find the exact value of cos 1 degree + cos 2 degrees + cos 3 degrees + ... + cos 357 + cos 358 degrees + cos 359 degrees.

asked by EC on October 24, 2016
3. ## Algebra 2

find the exact value of cos 300 degrees.

asked by Alex on May 19, 2014
4. ## 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
5. ## math

find the exact value of [sec(-30 degrees)- cot 120 degrees]/1-cosec^2(45 degrees) Find the exact value of [sin^2(355 degrees) + cos^2 (355 degrees)]/ tan^2 (30 degrees)

asked by lindsay on April 2, 2013
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 17, 2013
7. ## 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
8. ## Math

1. Find the value of Sin^-1(-1/2) a. -30 degrees b. 30 degrees c. 150 degrees d. 330 degrees 2. Find the exact value of cos(-420 degrees) a. -1/2 b. 1/2 c. sqrt of 3/2 d. -sqrt of 3/2 3. p(-9/41, 40/41) is located on the unit circle. Find sin theta. a.

asked by Belden on April 5, 2008
9. ## Trig

What is the exact value of cos 40 degrees cos 50 degrees minus sin 40 degrees sin 50 degrees do you know the formula cos(A+b) = cosAcosB - sinAsinB now compare it with your cos 40 degrees cos 50 degrees minus sin 40 degrees sin 50 degrees

asked by Michael on March 28, 2007
10. ## Algebra 2

Find the exact value of each expression if 0 degrees < theta < 90 degrees If tan (theta) = 1/2 , find cos(theta) If cos(theta) = 8/17, find csc (theta) Find the exact value of each expression is 180 degrees < theta < 270 degrees 7. If tan (theta)= 1, find

asked by Amy on May 7, 2015
11. ## math

Find the exact value of 1. tan 75 degrees 2. Cos 15 degrees 3. Sin 105 degrees

asked by lindsay on May 21, 2013
12. ## 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
13. ## Calculus

Find the exact values of the following. cos 270 degrees = 90 degrees, value = 0. Sin 180 degrees = 180-90 = 90 = 1, but its supposed to be zero, don't know how to get that:\ Confused with tan 240 degrees as well.

asked by -Untamed- on October 24, 2011
14. ## 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
15. ## 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 10, 2009
16. ## TRIG/ALGEBRA

1) Find the exact value. Use a sum or difference identity. tan (-15 degrees) 2) Rewrite the following expression as a trigonometric function of a single angle measure. cos 3x cos 4x - sin 3x sine 4x

asked by cheyanne on February 24, 2012
17. ## trig

give exact value of cos 75 degrees. give exact value sin 15 degrees. give exact value sin 225 degrees. You will have to use the addition relations here. Notice 75 is 30 +45, 15 is 45-30, and 225 is 180 + 45. I will be happy to critique your work.

asked by Matt on January 18, 2007

a. Use the formulas for lowering powers to rewrite the expression in terms of the first power of cosine: (cos^4)x (or cos*x to the 4th power) b.Use an appropriate Half- Angle Formula to Find the Exact value of the expression: 1. tan 15(Degrees) 2. cos

asked by Tricia on March 3, 2014
19. ## Mathmatics

a. Use the formulas for lowering powers to rewrite the expression in terms of the first power of cosine: (cos^4)x (or cos*x to the 4th power) b.Use an appropriate Half- Angle Formula to Find the Exact value of the expression: 1. tan 15(Degrees) 2. cos

asked by Tricia on March 3, 2014
20. ## Trigonometry

use the appropriate trig identity (sum and difference, half angle, double angle) to find the exact value. 1)cos 255 degrees 2) sin 165 degrees 3) tan 285 degrees

asked by Jennifer on March 3, 2011
21. ## Math

find the exact value of cos 15 degrees.

asked by Alessiah on December 5, 2014
22. ## Proving Identities

Find the exact value of cos 75 degrees.

asked by Anonymous on September 4, 2009
23. ## 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
24. ## Trignometry questions EASY HELP

1. Which is a solution to the equation below? sin2xsecx=1 2. What is the exact value of cos15 degrees? 3. Which expression is equivalent to the expression below? cos^2 xsin^2? 4. What is the exact value of cos2theta? one side is 8 and the other is 15 5.

asked by kalakalikalakali on June 29, 2011
25. ## 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
26. ## trig math 30

Find the exact value of cos 8 degrees cos 38 degrees + sin 8 degrees sin 38 degrees

asked by Sandy on March 6, 2010
27. ## Algebra 2

Find the exact value of cos 315 degrees. answers: 3/2, -1/2,2/2, -2/2

asked by Pam on May 19, 2014
28. ## trig

Find the exact value by using a half-angle identity. cos 22.5 degrees

asked by Omar on October 11, 2011
29. ## math

Determine the exact value of the following. a) sin300 degress b) tan (-135 degrees) c)csc150 degrees d) sec45 degrees e) cos 4pi/3 f) sin (-3pi/4)

asked by Anonymous on October 18, 2016
30. ## 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 14, 2012
31. ## Algebra 2 Honors

Find the exact value by using an appropriate sum or difference identity. cos(165) degrees

asked by Christine on June 6, 2010
32. ## 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 14, 2012
33. ## 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 23, 2012
34. ## math

1)In triangle ABC, C=60 degrees, a=12, and b=5. Find c. A)109.0 B)10.4 C)11.8 D)15.1 I chose B 2)Which triangle should be solved by beginning with the Law of Cosines? A)A=115 degrees, a=19, b=13 B)A=62 degrees, B=15 degrees, b=10 C)B=48 degrees, a=22, b=5

asked by Jon on February 11, 2008
35. ## Trig

Can someone check my answers so far? 1. Find the exact value of tan(-3ð) Answer: tan(-3ð) = tan (-3 + 2ð) = tan (-ð) = tan (-ð + 2ð) = tan(ð) = sin (ð)/cos(ð) = (0)/(-1) = 0 Exact value is 0 2. Solve triangleABC is C = 90 degrees, B = 20 degrees,

asked by Kasey on January 29, 2009
36. ## trig

using the trigonometric identities find the exact (radical form) value of cos (105 degrees)

asked by spencer on April 13, 2010
37. ## Algebra II

Find the exact value of cos 375 degrees. Answer: (sqrt6 + sqrt2)/4 Is this correct?

asked by Lucy on April 19, 2008
38. ## PRE CALC

1. solve tan36 degrees- tan2degrees/ 1+tan36 degrees tan 2 degrees as a single function. 2. Find the exact value of sin (α-β) if sina=4/5 and cos β= -9/41 terminal side of α lies in I and terminal side of β lies in III 3. If cosx=1/12 and sinx > 0,

39. ## Studying for Pre Cal exam

Find the fourth roots of − 1/2 + (square root)3/2 i Write the roots in trigonometric form. A - w 1=cos(35°)+isin(35°) w2 =cos(125°)+isin(125°) w3 =cos(215°)+isin(215°) w4 =cos(305°)+isin(305°) B - w1 =cos(40°)+isin(40°) w2

asked by Lottie on July 13, 2016
40. ## Algebra II

Find the exact value of sin(theta/2) if cos theta = 2/3 and 270 degrees

asked by Lucy on April 19, 2008
41. ## 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
42. ## Trig

If tan a= 12/15, 0 degrees < a < 90 degrees, then find the exact value of each of the following: A. Sin a/2 B. Cos a/2 C. Tan a/2

asked by Erin on June 12, 2018
43. ## math

how to define arc cosine(cosine x) for -360 deg

asked by mahima on June 1, 2007
44. ## 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

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
46. ## 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
47. ## Math/precal

Find the exact value of: (1-sin^2 pi/2)/(cos^2 28 degrees + sin^2 28 degrees)

asked by Maxx on March 16, 2016
48. ## 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
49. ## Physics

How do I find Vector Resolution F = 0.300 g N, theta = 60 degrees. Do I take tan inverse (.3 sin 60/.3 cos 60)?

asked by Devin on September 17, 2012
50. ## 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. sin2ƒÆ = (sqrt 3)/2 2. sin^2ƒÆ = cos^2ƒÆ + 1/2 3. sin 2x

asked by anon on March 3, 2011
51. ## Pre Cal

2cos 4theta + 1 = 0 i know how to find the degrees (the last step of the problem), but i don't know how to start the problem. Could someone please show me the steps? I assume you mean cos (4 theta) and not (cos theta)^4 cos (4 theta) = -1/2 The angles with

asked by Marie on March 7, 2007
52. ## 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 22, 2007
53. ## 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
54. ## Pre Calc.

Use the sum or difference identity to find the exact value of sin255 degrees. My answer: (-sqrt(2)- sqrt(6)) / (4) Find the value of tan (alpha-beta), if cos alpha= -3/5, sin beta= 5/13, 90

asked by Patrick on April 22, 2009
55. ## Math

In triangle PQR, angle Q= 90 degrees, angle P= 60 degrees and angle R= 30 degrees. PR= 1 unit. Extend side QR to T such that PR= RT. Join PT. Calculate the exact measure of angle T. Determine the exact value of lengths needed to find tan T and then find

asked by Kausar on February 23, 2017
56. ## 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
57. ## Math

Determine the exact value of cos 465 degrees a) √3 + √2/2 b) √2 + √3√2/4 c)√2 - √3√2/4 d)2+√2-√3√2/4

asked by Jake on January 27, 2012
58. ## Precalculus

Determine the exact value of cos 465 degrees a) √3 + √2/2 b) √2 + √3√2/4 c)√2 - √3√2/4 d)2+√2-√3√2/4

asked by Melinda on January 29, 2012
59. ## math b

if sinx=(4/5), where 0 degrees

asked by manda on April 10, 2007
60. ## Math (FST)

1. Give exact value of tan(theta) if cos(theta)=-2/7 and pi/2

asked by Ryan on September 25, 2008
61. ## Trigonometry

a. Find the exact value of sin (theta - pi/6) b. Find the exact value of cos (theta - pi/4) c. For what numbers x, -2pi less than or equal to x less than or equal to 2pi does cos x = -1 d. What is the range of the cosine function? e. For what numbers x,

asked by Cassie on April 9, 2011
62. ## 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
63. ## math, trig

What is the exact value of the cos of 23pi/12? (Twenty-three pi over 12, which is = to 345 degrees.) Thank you

asked by roger on April 26, 2010
64. ## trigonometry

We begin by setting t=sin 18 degrees we weill think of t an an "unknown" angle and solve to get the exact value. Use a double angle formula to show that cos 36 degrees=1-2t^2

asked by Anonymous on November 12, 2012
65. ## 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
66. ## 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 13, 2015
67. ## math

PLEASE HELP ME WITH THIS TRIGONOMETRY QUESTION!!? Edit Express each of the following in terms of another angle between 0 degrees and 180 degrees a. sin 50 degrees b. sin 150 degrees c. cos 45 degrees d. cos 120 degrees Update: we have not yet learnt it in

asked by becky2000 on September 2, 2016
68. ## Math

Find the exact value of the trig function below. cos a/2 if cosa = - 31/49 (assume cos a/2 is negative)

asked by Rachel on March 19, 2017
69. ## Math

Find the exact value of the trig expression given that sin u = -5/13 and cos v = -4/5. u and v are in the second quadrant. cos(v - u)

asked by Anonymous on October 25, 2015
70. ## Math

If sin(x) = 4/5 and cos(y) = 5/13 with both x and y terminating in quadrant 1 find the exact value of cos(x-y) I know that the denominator will be 65

asked by Bryan on March 19, 2010
71. ## Trigonometry

What is the exact value of the cos of 23pi/12? (Twenty-three pi over 12, which is = to 345 degrees.) Thank you, Roger

72. ## Trigonometry

1. Find the exact value of the following (Think identity) Cos(2 Arccos(5/13)) 2. Solve the following equation for 0° ≤ Θ < 360° Sec(Θ)= tan(Θ) + cos(Θ)

asked by Chris on April 26, 2010
73. ## Trigonometry

Find the exact solutions of the equation in the interval [0, 2π). (cos 2x) - (cos x)=0

asked by Syndra on October 11, 2014
74. ## Math

Find the exact value: 1.) cos^-1(sin(pi/2)) 2.) arccos(cos(7pi/2))

asked by Tori on December 7, 2014
75. ## Math

Find the exact value: 1.) cos^-1(sin(pi/2)) 2.) arccos(cos(7pi/2))

asked by Tori on December 8, 2014
76. ## Pre calc

Let sin u=-8/17 and cos v= 12/13, with pie

asked by Lizzy on November 17, 2015
77. ## Mathematics

1. Show that Sin3è - Cos2è = (1 - Sinè)(4Sin^2è + 2Sinè - 1). Without using a calculator, show that è = 18 degrees is an exact solution of the equation Sin3è = Cos2è. Justifying your answer, find the exact values of: i) Sin18 degrees. ii) Sin234

asked by Edwards on August 3, 2011
78. ## 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

Find a simplified expression for cos(tan^(-1)(x/5)) Evaluate cos(sin^(-1)(1/11)), giving your answer as an exact value (no decimals)

asked by Anonymous on April 3, 2013
80. ## Trigonometry

Using exact values, find the value of: a. 12 sin 30 degrees ¨C 6 tan 45degrees + sec 45degrees / 52 12-1/2-6*(1) + ¡Ì2/52=¡Ì2/52 12-1/2-6+¡Ì2/52 what should i do next?? b. Sin2A + tan3A/2 - cos A + sec(a+ 15) Sin2A + tan3A/2 - cos A + sec(a+ 15)=

asked by Anon on January 1, 2011
81. ## Pre-Calculus

Find two exact values of theta in degrees (0 less than or equal to theta < 360°) if cos theta = -(square root of 2)/2.

82. ## ODU

FIND THE EXACT VALUE OF COS U 4/5, PI/2

asked by TINA on September 28, 2012
83. ## math;) Law of Cosines

Two satellites are in Earth's orbit and are 424 km apart. If an observer is 658 km away from satellite A and 471 km away from satellite B, what angle must the observer turn his telescope to change his view from one satellite to another? a. 40.0 degrees b.

asked by girly girl on April 25, 2018
84. ## 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
85. ## Trigonometry

Hello, everyone: I am working on finding the exact values of angles that are less common and are therefor not found easily on the Unit Circle (at least, they are not labeled). For example, the problem I am asking about is: 10) Find the exact values of the

asked by Timothy on March 17, 2008
86. ## Math

For value cos (8ð/3). b) write cos (8ð/3) in terms of an algebraic sign and cosine of the reference angle find the exact value of what you found in part b using a cheating chart. no decimals please

asked by sam on February 16, 2011
87. ## Math

State the exact values of the following. cos(360 degrees) sec(7pi/2) tan(-9pi/2) How do I do these? Thanks!

asked by Jillian on December 9, 2011

1) Use the cofunction identites to evaluate the expression without the aid of a calculator. cos^2 18 degrees + cos^2 72 degrees. Would I use the forumula cos(pi/2 - Q) = sin Q

asked by Abby on February 28, 2010
89. ## trig

How do I solve this? If cos x= 3/5, find the exact value of cos 2x

asked by Paul on December 1, 2008
90. ## physics

A pushes with force of 300 N at 25 degrees. B pushes with force of 275 N at 160 degrees. C pushes with force of 325 N at 300 degrees. Find resultant force. I got 187 N at -19 degrees or 161 degrees. Correct? or could you explain more please? Thank you.

asked by Anonymous on November 7, 2010
91. ## 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

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
93. ## Maths

Find the exact value of cos^2(15°)-cos^2(30°)+cos^2(45°)-cos^2(60°)+cos^2(75°)

asked by Bob on May 9, 2014
94. ## 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 9, 2015
95. ## Maths

Determine the exact expression for the following. - cos(pi/4)=(x/60) I got x=60/√2 Is that correct? Also, I had a lot of trouble with this one: cos(pi/6)=(z/60) I got z=(√3 (60/√2))/2 That doesn't seem right, but I don'r know what I', doing wrong.

asked by Lucy on November 8, 2009
96. ## 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
97. ## trig

find the exact solutions (è in degrees) sin^2è+2cosè=-2 change the sin^2 to 1-cos^2, then rearrage the equation into quadratic form, use the quadratic equaion.

asked by Devon on April 16, 2007
98. ## Precalculus

An airplane is flying on a bearing of 285 degrees at 480 mph. A wind is blowing with the bearing 265 degrees at 30? a. find the component from of the velocity of the airplane b. find the actual speed and direction of the airplane 485 sin 75 degrees -485

asked by Anonymous on April 25, 2018
99. ## 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
100. ## 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 13, 2015