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

4,795 questions, page 30
1. ## Pre- calculus

Change the equation to rectangular coordinates: r= 2(sin theta-cos theta)

asked by Meredith on December 19, 2016
2. ## trig

How do I solve.... Tan 2(theta) - Cos 4(theta) = 0 Domain: (0-360 degrees) Thank you.

asked by Heather on December 11, 2011
3. ## Calc 3

Calculate the velocity and acceleration vectors, and speed for r(t)=⟨cos(6t),sin(t),sin(6t)⟩ when t=5π/6 .

asked by ally on February 1, 2019

1. sin(tan^-1(4/3))=4/5 2. find the angle whose tangent equals 0. tan^-1(cos(pi/2))=0

asked by Lizzie on January 28, 2014
5. ## Pre-Cal (verifying trig identities)

How would you verify the identity? sin^1/2x-cosx-sin^5/2xcosx=cos^3xradsinx

asked by Crystal on February 12, 2009
6. ## pre calculus

change the equation to rectangular coordinates: r= 2(sin theta -cos theta)

asked by Meredith on December 19, 2016
7. ## Trig identities

Has a negative -5/13 Steve. If angles x and y are in the same quadrant and sin x =3/5 and cos y= -5/13 determine the value of sin (x-y)

asked by Luke on December 8, 2016
8. ## Math

If A and B are acute angle such that SinA=8/17 and CosB=3/5.Find 1, Cos(A+B) 2, Sin(A+B) 3, Sin(A-B)

9. ## Trigonometry

Given that sin(2θ)=2/3, the value of sin^6θ+cos^6θ can be written as a/b with a and b as coprime positive integers. Find a+b.

asked by Shin on May 27, 2013
10. ## precalc

tan(θ + ϕ); cos(θ) = − 1/3 θ in Quadrant III, sin(ϕ) = 1/4 ϕ in Quadrant II evaluate the expression

asked by help! on April 24, 2016
11. ## Trigonometry

What is the value of tan (Arc cos 15 seventeenths)? 1. 8/15 2. 8/17 3. 15/8 4. 17/8 Can you guys explain what the Arc means?

asked by Anon on June 10, 2018
12. ## calculus

Find the particular solution to y ′ = sin(x) given the general solution is y = C − cos(x) and the initial condition y(pi/2)=1

asked by Anonymous on July 17, 2015
13. ## calculus

Determine whether the sequence converges or diverges. If it converges, find the limit. an = cos^2(n)/3^n

asked by Anonymous on April 7, 2019
14. ## maths trigonometry,

find all solutions between 0 and 2pii for (tan theta =1)and (cos theta =negative 1/2).

asked by lughano on March 3, 2017
15. ## maths

can some one help me here : if 5 cos x + 3 = 0 and 180 degrees < x < 306 degrees , find the value of 3 tan x + 25 sin^2 x

asked by nokuphiwa on April 29, 2014
16. ## Trigonometry

If sin A=3/5 and cosB = 24/25 and angle A and angle B are both in quandrant 1. What is sthe exact value of cos (A-B)?

asked by Carol on April 25, 2011
17. ## Calculus

If tan(θ)=−7/2 and sin(θ)

asked by Rileigh on April 4, 2017
18. ## Trig

Find the algebraic expression that is equal to sec theta - cos (-theta)

asked by Amanda on March 24, 2016
19. ## trig

what is the exact value of cos(x+y) if tan=x sqare root 3 over 3 and sin y=square root 2 over 2?

asked by ebonee on March 8, 2012
20. ## Trig

Given sin= -√5/6 with π < u < 3π/2 and cos v= √3/5 with 0 < v < π/2 find sin(u-v) and tan(u+v). Please show work and simplify.

asked by Jane on March 8, 2016
21. ## math

determine the exact value of (cot pi/3) + (csc pi/3) / (cos pi/4). how is this calculated? i mean the steps to get the exact value?

asked by carli on April 7, 2014
22. ## calc

Find k so that the function is continuous on any interval. h(x) = k cos x 0 ≤ x ≤ 3π h(x)= 10 − x 3π < x I am confused on how to find k when it gives you 3pi? help please

asked by kim on September 27, 2016
23. ## Math

If A and B are acute angle such that SinA=8/17 and CosB=3/5.Find 1, Cos(A+B) 2, Sin(A+B) 3, Sin(A-B)

24. ## math

Find the volume generated by rotating the area between y = cos( 3 x ) and the x axis from x = 0 to x = π/ 12 around the x axis

asked by sk on September 29, 2011
25. ## math

Solve the following equation for theta (θ) over the given domain: √3 sin 2θ = cos 2θ Domain: 0 < θ < 360

asked by sweetG on July 5, 2008
26. ## Evaluating limits

Evaluate the limit. (If you need to use - or , enter -INFINITY or INFINITY.) lim x +sin(x)/(2x+cos(x)) as x goes to 0.

asked by mike on December 6, 2010
27. ## Precalculus

rewrite the following expression as an algebraic expression in x: cos(arcsin x) I have made X to be X/1 but from there I am lost.

asked by George on November 12, 2012
28. ## math- Trigonometry

If cos degree equals to 0.8641 What is Sin degree? I have no idea how to find this. Please help me. Thank you

asked by Simran on November 4, 2016
29. ## calculus check

Find the limit as x approaches 3 of [(2x^3-5x^2+7)/(3sin(xpi/6)-cos(xpi))] When I plugged in 3, I got 4.

asked by Jeff on April 26, 2015
30. ## Calulus

Given \displaystyle \int_0^{\frac{3\pi}{2}} x^2\cos x \, dx = a - \frac{b\pi^2}{c}, where a, b and c are positive integers and b and c are coprime, what is the value of a + b + c?

asked by John on March 10, 2013
31. ## Math (triangles)

Given b=48, A=36 degrees find the remaining parts of the right triangle. a= a)51 b)35 c)66 d)29 and c= a)35 b)26 c)82 d)59 This one I'm lost on! a = b tan A = 34.8 (round it off to 35) c = b/cos A = 59.3 (round it off to 59)

asked by melinda on March 9, 2007
32. ## calculus

Find all values of x in the interval [0, 2π] that satisfy the inequality. (Enter your answer using interval notation.) 14 cos(x) + 7 > 0

asked by Anonymous on September 19, 2011

Hi everyone, I've been stuck on this question. Please anyone help. Show step by step and answers. Thank you. - Determine the​ quarter point of y=−cos(2x−π) THANK YOU.

asked by chichi on August 3, 2016
34. ## precal

use the given info. to find the exact value of the trig function. csc u=-6/5, tan u is greater than 0 Find cos u/2

asked by john 2020 on March 18, 2010
35. ## MATH ANALYSIS

How do you simplify these questions?: 1. cos^2(x/2)-sin^2(x/2) 2. 2cos^2(3A)-1 3. sin 2x/1+cos2x I think number 3 is tan 2x? The other two I don't know. Thanks for the help

asked by anonymous on May 25, 2010
36. ## Calculus

Find the area of the region that lies inside both curves. r = (3)^(1/2) cos (theta), r = sin (theta)

asked by Mercedes on June 9, 2010
37. ## Calculus

Integrate (1/2)sin(x^(1/2))dx. I've tried using u-substitution, with u=sin(x^(1/2)). du would then = ((1/2)x^(-1/2))(cos(x^(1/2))). As you can see, this only make the problem more complicated. I don't get what to do. Thank you in advance!

asked by W on January 2, 2012
38. ## pre-calculus

Write the first expression in terms of the second if the terminal point determined by the t is in the given quadrant: sin t, cos t; quadrant 2

asked by Molly on January 16, 2012
39. ## math

if 0

asked by soumitra on August 29, 2014
40. ## maths

(Sin^3x-cos^3x)/(sinx-cosx) – cosx/sqrt(1+cot^2x)-2tanxcotx=-1 where x∈(0,2pi) general value of x.

asked by anil jha on October 17, 2012
41. ## Math

Use the Intermediate Value Theorem to show that there is a root of the given equation in the specified interval. cos x = x. How do I begin this problem? According to the theorem, a=0, b=1 and N=x?

asked by KC on September 2, 2012
42. ## Calc

Use the derivative to determine whether the function is strictly monotonic on its entire domain and therefore has an inverse function. f(x) = cos [(3x)/2]

asked by Erica on December 6, 2010
43. ## pre calc

tan(θ + ϕ); cos(θ) = − 1/3 θ in Quadrant III, sin(ϕ) = 1/4 ϕ in Quadrant II I am really struggling with this idk why I keep getting the wrong answers

asked by Andy on April 11, 2017
44. ## mathematics

The plane curve is given by the equation R(t)= ( ln sin t)i + ( ln cos t)j. find the unit normal vector to the curve t= ¤Ð/6.

asked by sibongile on June 27, 2014
45. ## Math

Write each complex number in rectangular form? I need help with this. :/ 2(cos120°+i sin 120°) and 4(cos 7π/4 + i sin 7π/4) ?

asked by Fernando on October 17, 2010
46. ## Physics-Check

A missile launches at a velocity of 30.0 m/s at an angle of 30.0* to the normal. What is the maximum height the missile attains? (((30)*cos(30))^2)/(2*9.8) )

asked by LeRoy on April 10, 2009
47. ## Calc I

How do I find the derivative for the sqrt(sin(e^(x^3)*cos(x)))??? I know this is a combination of the chain rule and product rule. Please help!

asked by Coolio on June 30, 2013
48. ## calculus 2

Integral of 63x(cos(x))^2 dx I got: 63x^2/4 +63sin(2x)/4 +63cos(2x)/8 +C I keep getting this answer but the online site says it's wrong.

asked by Anonymous on September 6, 2013
49. ## trig

if point P is a point on the terminal side of 0, and 0 is in standard position, find sin 0,cos 0 and tan 0. 1. P(-6,8) 2. P (1,3) 3. P (-2,-40), 4. P (-5, -12)

asked by shawn on May 14, 2011
50. ## Calculus (Arc Length)

Consider the helix parametrized with the vector equation r(t)=cos t i+ sin t j + t k. The length L of the helix between the points (1,0,0) and (1,0,6π) is equal to aπ. What is the value of a^2?

asked by Shin on June 20, 2013
51. ## Trigonometry

Could someone please help me with the following q's I'm having some trouble: 1.) cot θ (theta) = 0.791, find sec θ and tan θ 2.) tan θ = 9/40, what is the value sin^2θ + cos^2θ

asked by Kevin on November 26, 2013
52. ## Math

Solve the equation for x in the interval 0

asked by Diana on January 11, 2010
53. ## trig

Find the sign of the expression if the terminal point determined by t is in the given quadrant. cos t X sec t in any given quadrant

asked by Katie on December 1, 2010
54. ## Trigonometry

1. Using the definitions of odd and even functions, explain why y=sin x+1 is neither odd nor even. 2.Using the definition of an even function, show that y=-cos is even.

asked by Ryan on March 1, 2016
55. ## Physics

A string vibrates according to the equation y' = (0.30 cm) sin[(π/3 cm-1)x] cos[(55π s-1)t] What is the speed of a particle of the string at the position x = 1.5 cm when t = 9/8 s?

asked by Kyle on December 3, 2011
56. ## Calculus

A particle moves along a line so that at any time t its position is given by x(t)=2(pi)t+cos(2(pi)t). Determine the particle's maximum velocity.

asked by MEG on November 15, 2010
57. ## math

State a trigonometric ratio that is equivalent to each of the following trigonometric ratios Sin 3pie/10 Cos 6pie/7

asked by Melissa on November 10, 2012
58. ## Math

Really Stumped on this one, any help would be great! Thanks! Find the exact value of cos 2x using the double angle formula. cosx=−2/13 cosx=-2/13 where π2

asked by Daemon on February 7, 2018

Determine the solutions for: (cos x)/(1 + sinx) + (1 + sinx)/(cosx) = 2 in the interval x is all real numbers, such that [-2 pi, 2pi]

asked by Anonymous on November 20, 2009
60. ## Pre-Calculus

How would you prove/Verify this Identity. x=theta (cosx+sinx-sin^3x)/(sinx)=cotx+cos^2x

asked by Beatrice on May 10, 2012
61. ## MATH

Rewrite cos(arcsin(v)) as an algebraic expression in v. i know that the answer is squroot of 1-v^2 but i don't know the process of how to come to this answer. Thanks for the help!

asked by MISS SUE PLEAE HELP on December 4, 2011
62. ## Math

Rewrite cos(arcsin(v)) as an algebraic expression in v. i know that the answer is squroot of 1-v^2 but i don't know the process of how to come to this answer. Thanks for the help!

asked by Bob on December 4, 2011
63. ## math

in a oblique triangle ABC ,it is known that tan A=3/4,cos B=5/13 an AB=10cm find sinC,side AC, and side BC

asked by zel on January 26, 2015
64. ## physics

On take off, the combined action of the engines and wings of an airplane exerts a(n) 7767 N force on the plane,directed upward at an angle of 59.1 degrees above the horizontal. The plane rises with constant velocity in the vertical direction while

asked by alexa on July 14, 2011
65. ## Pre-Calculus

How can this identity be proved/verified? cscx-sinx=1/(secxtanx) I have tried starting on both sides of the equation to get to the other. By starting on one side of the equation and manipulating it to make it look like the other side, the identity will be

asked by Corin on May 3, 2007
66. ## calculus

What analytic method steps are required to find the limit of cos x-1/2x^2 ? Limit greater than 0. Estimating -0.25 but stalled ....

asked by George on September 9, 2010
67. ## math

find the points to the curve y=(cos x)/ (2 + sin x) at which the tangent is horizontal... can you explain how get the answer thoroughly and step by step...

asked by khela on October 28, 2010
68. ## pprecalc

the function is one of the form y=g(x) +cosbx. find two linear functions y1 and y2 related to g such that y1 is less than or equal to y is less than or equal to y2. a. y= 2x + cos x b. y= 1-0.5x+ cos2x

asked by greeny on October 2, 2012
69. ## trig

Use De Moivre's theorem to simplify the expression. Write the answer in a + bi form. [2(cos 240° + i sin 240°)]^5

asked by tony on June 28, 2013
70. ## calculus

What analytic method steps are required to find the limit of cos x-1/2x^2 ? Limit greater than 0. Estimating -0.25 but stalled ....

asked by George on September 9, 2010
71. ## Math

With figure, img19.imageshack.us/img19/2135/81gd.png prove: tan(x/2) = sin(x)/(1+cos(x)).

asked by Mary on July 24, 2013

Use Green's Theorem to evaluate C F · dr. (Check the orientation of the curve before applying the theorem.) F(x, y) = y2 cos x, x2 + 2y sin x C is the triangle from (0, 0) to (1, 3) to (1, 0) to (0, 0)

asked by Taylor on November 9, 2016
73. ## math

Roughly sketch the region enclosed by the curves y = sin x, y = cos x and the x - axis between x = 0 and x = p/ 2 . Also find the area of this region.

asked by usha on March 14, 2015
74. ## math

how would you determine a conic represented by the polar equation r=a*cos(x)+b*sin(x). then how would you convert the equation to rectangular form? please help

asked by mike on May 14, 2009
75. ## MATH!

asked by ????? on January 30, 2012
76. ## math

.The graph of f(x)=cos(x) is transformed to a new function, g(x) , by stretching it horizontally by a factor of 4 and shifting it 1 unit up. What is the equation of the new function g(x) ?

asked by Mason on April 8, 2018
77. ## Calculus

A particle moves along the x-axis and its position for time t is greater than or equal to 0, is s (t)=cos(2t)+sec(t). When t=pi, the acceleration of the particle is

asked by Jessica on November 6, 2016
78. ## Geometry/Trig.

Let angle A be and acute angle in a right triangle. Approximate the measure of andgle A to the nearest tenth of a degree. cos A = 0.11

asked by Chica on January 30, 2011
79. ## Calculus 2

Find the volume of the solid obtained by rotating the region bounded by the curves y=cos(X), y=0, x=0, x=pi/2 about the line y=-1 Volume=?

asked by RaShawnya on February 20, 2018
80. ## calculus

using L'Hospital's rule, evalutate; LIM as x->0 e^x +cos x / e^x + sin x I'm at LIM x->0 e^x+cosx / e^x +sinx but now I at a lost as to how to proceed.

asked by redgy on November 21, 2011
81. ## trig

{Given: cos(A)=\frac: sqrt{203}/{18} {Find: tan(A) Find the positive value of the above in simplest radical form.

asked by bbee on March 19, 2011
82. ## precalculus

For the acute angle with sin theta=3/5, find cos theta, tan, cot, csc, sec.

asked by tina on December 3, 2009
83. ## Calculus

A weight oscillates in a vertical motion according to the position function y(t)=-5 cos(t). Assuming t≥0, when will the acceleration if the weight be zero for the first time?

asked by Anonymous on March 27, 2014
84. ## Calculus

Show that the curves r=acos(è) and r=cos(è) intersect at right angles. can it be shown that the derivative of one is the negative reciprocal of the derivative of the other?

asked by Amy on April 5, 2007
85. ## calc

Consider the vector function given below. r(t) = 7t, 3 cos t, 3 sin t (a) Find the unit tangent and unit normal vectors T(t) and N(t). i found T(t) but I can't get N(t)

asked by sara on September 10, 2014
86. ## Precalculus II

Find the inverse of: f(x) = -5 +11arccos(7^x - 9) Find exactly all the real solutions for each of the following equations. a. Sin(x) = - square root 3/2 b. 1 + cos(3x-pi/4) = 1/2

asked by hfx on March 11, 2014
87. ## Calculus

Determine if Rolle's Theorem applies to the given function f(x)=2 cos(x) on [0, pi]. If so, find all numbers c on the interval that satisfy the theorem.

asked by Ky on March 6, 2011
88. ## HELPPPPPPP (TRIG)

find, to the nearest minute, the solution set of 1- sin x = 3 cos^2 x over the domain 0 degrees to 360 degrees

asked by HELPPPP on May 20, 2010
89. ## physics repost

What should be the angle between two vectors of magnitudes 3.20 and 5.70 units, so that their resultant has a magnitude of 6.10 units? cos=a^2+b^2-c^2/2ab cos10.24+32.49-37.21/(2*3.20*5.70) = 99 degrees

asked by Anonymous on April 16, 2008
90. ## Trig Identities

Explain why Sin of theta= -The square root of 1-cos^2 theta is not an identity, using either graphical or numerical reasoning.

91. ## Precalculus

Solve for x given the interval of [0,2pi). cos^2x=2+2sinx I got (3pi)/2 or 270 degrees.. By the way, does the notation [0,2pi) mean 0

asked by Anonymous on May 5, 2014
92. ## mathematics

find the mean and RMS of v=25sin50πt over the range t=0 to t=20ms using integration. i have integrated to: v=-cos(50πt)/2π+c but i don't know how to get the mean and rms.

asked by jerome on April 21, 2014
93. ## Precalculus

Solve for x given the interval of [0,2pi). cos^2x=2+2sinx I got (3pi)/2 or 270 degrees.. By the way, does the notation [0,2pi) mean 0

asked by Anonymous on May 4, 2014
94. ## trig

If cos 0 = - 1/2 and tan 0 > 0, find the quadrant that contains the terminal side of 0, and then find the exact values of the other five trig functions of 0.

asked by shawn on May 14, 2011
95. ## Math

Without using calculator,evaluate Sin15 deg,Cos 15 deg,Sin 75deg. O need the answer urgently pls.

asked by Prince on November 14, 2011
96. ## Trigonometry

Use De Moivre's Theorem to write the complex number in trigonometric form (cos(2pi)/7)+ i sin((2pi)/7))^5

asked by O on May 25, 2015
97. ## Math

if sin theta =1/2 and cos theta= √(3)/2. find tha values of tan θ, cot θ, sec θ and cscθ.

asked by Anonymous on March 8, 2019
98. ## Trig.

How's the rule go on evaluating compositions of functions? Is it that sine is positive in first and second quadrants, while cos/tan are positive in the first and the fourth?

asked by Sam on December 21, 2009
99. ## calculus

find the derivative of f(x)=x^2sec^2(3x) also with g(x)=sqrt(cosxsecx) i get zero because cos and sec cancel each other out and derivative of a constant is zero... am i doing something wrong?

asked by anonymous on March 20, 2011
100. ## geometry!!!

Write the ratios for sin A and cos A. The triangle is not drawn to scale. *right triangle. 14 on the side. 50 on the slant. and 48 on the bottom.

asked by Anonymous on February 20, 2013