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

4,795 questions, page 38
1. ## Maths

a and b are perpendicular vectors.a=(2i+3j) and b=ti+dj(d>0 and i and j are unit vectors) and |b|=1 Find t and d? I know we have to use the cross product here. a.b=|a||b|*cos(π/2) (2i+3j)(ti+dj)= √13*1*0 2t+3j=√13*0 How do we find t and d?

asked by Josh on August 1, 2017
2. ## calculus

Find the exact value of: cos(arctan(2) + arctan(3)) Please explain how you got your answer. I have the answer, but I don't know how to get to it.

asked by Jane on February 21, 2009
3. ## math

cot^-1(2tan(cos^-18/17))+tan^-1(2tan(sin^-18/17))=tan^-1300/161

asked by hasee on April 4, 2013
4. ## Math

Suppose sinA = 12/13 with 90º≤A≤180º. Suppose also that sinB = -7/25 with -90º≤B≤0º. Find cos(A + B).

asked by TeeKay on October 14, 2014
5. ## trig

{tan^2x+cotx divided by tanx-cotx} is equal to {1 divided by sin^2x-cos^2x}

asked by stacey graham on March 26, 2010
6. ## Trigonometry

Given sin x = 4/7 and cos x = negative square root of 33 over 7, find cot x. I think it's square root of 33 over 4!

asked by Jennifer on January 9, 2010
7. ## Math

Find the value of b, if any, that will make the function differentiable at x = 0 g(x)= { x+b, x

asked by Henry on November 18, 2014
8. ## Trigonometry

Prove that tan (Beta) sin (Beta) + cos (Beta) = sec (Beta) Please explain.

asked by Cynthia on August 3, 2012
9. ## Math

Find the value of b, if any, that will make the function differentiable at x = 0 g(x)= { x+b, x

asked by Henry on November 18, 2014
10. ## f math

please what is the answer to this f math question......1-cos^2X=0 for 0°less dan equals X..then X less dan equals 270

asked by mercy on November 20, 2016
11. ## Pre calculus

Find the value for sin(theta), cos(2 theta)=3/4 and 270 degrees

asked by Leslie on May 5, 2016
12. ## Math

Find the value of b, if any, that will make the function differentiable at x = 0 g(x)= { x+b, x

asked by Robby on November 16, 2014
13. ## trig

verify the identity: sec(beta)+ tan (beta)= cos(beta)/ 1-sin(beta)

asked by stacey graham on March 26, 2010
14. ## Math

What is cos 2theta for sin theta = -2/13 in 180 degs < theta < 270 degs?

asked by Anonymous on May 12, 2015
15. ## trigonometry26

If 1+sin^2 theta = 3sin theta cos theta, then prove that tan theta =1or 1/2

asked by pankaj khanna on July 2, 2015
16. ## calculus

find f'(x) for the following: f(x)= cos^5(4x-19) I keep getting 20cos^4(4x-19)sin, but the answer is supposed to be -20cos^4(4x-19)sin(4x-19). I can't seem to get there with derivatives

asked by redgy on March 16, 2011
17. ## Calculus

SHOW WORK PLEASE!!!!! The displacement (in centimetres) of a particle moving back and forth along a straight line is given by the equation of motion s = 4 sin(πt) + 2 cos(πt), where t is measured in seconds. (Round your answers to two decimal places.)

asked by Willow on September 2, 2018

SHOW WORK PLEASE!!! The displacement (in centimeters) of a particle moving back and forth along a straight line is given by the equation of motion s = 2 sin πt + 3 cos πt, where t is measured in seconds. (Round your answers to two decimal places.) (a)

asked by TENSHI on February 2, 2014
19. ## MATH - HELP ME PLEASE!!!!

Consider the following by looking at the website below. www.webassign.net/waplots/3/a/808112f7e2262ae957c47b37497635.gif a) Find the length of the third side of the triangle in terms of x. b)Find θ in terms of x for all three inverse trigonometric

asked by Hi😱 on February 21, 2019
20. ## Pre-Cal

Solve the given equation. (Enter your answers as a comma-separated list. Let k be any integer. Round terms to two decimal places where appropriate.) cos θ = −1/2 1).θ= Answer-->(2π/3)+2πn, 4π/3+2πn 2). List six specific solutions a). b). c). d).

asked by Amber on July 11, 2016
21. ## maths

I'm reviewing for my exams, and I was sure that I was comfortable with solving trigonometric identities, but now that I'm looking at ones on my review, I'm not so sure. Could someone please show me, step by step, how to answer one? [cos^2theta] / [1

asked by anonymous on June 18, 2010
22. ## Math

Use inverse trigonometric functions to find a solution to the equation in the given interval. Then find solutions? cos x = -0.6 , 0

asked by George on November 8, 2014
23. ## trigonometry

can you explain to me in details please of how these type of questions can be answered without using a calculator to find the direct answer. Find the following functions correct to five decimal places: a. sin 22degrees 43' b. cos 44degrees 56' C. sin

asked by anon on January 13, 2011
24. ## Math

Hello! I have been learning about proving identities and can do simple ones but lately I have been really struggling. I am currently stuck on this problem. cos(A-B)/tan(A)+cot(B) = sin(B)/sec(A) I managed to get to: cosAcosB-sinAsinB/(sinA/cosA) +

asked by Jenny on April 23, 2019
25. ## Trig

I need help with these kind of problems! Can someone tell me how to work this problem out? Given tan0=2 square root of 5 over 4, and sin0

asked by Jennifer on October 29, 2009
26. ## Physics

A motorboat is headed [W35ºN] with its engine set to move the boat at 25 km/h in still water. The current is flowing at 18 km/h [S]. What is the velocity of the boat relative to the shore? My work: cos(35º)=x/25 25cos35=x x=20km/h I have an issue with

asked by Lauren on May 3, 2017
27. ## COLLEGE PHYSICS

a 58kg skier is coasting down a 25degree slope with a kinetic friction force of 70N. initial speed is 3.6 m/s and distance traveled is 57m. find final velocity? i need some help on this i don't know where to start. i know W=F x cos theta x distance is the

asked by natali on October 18, 2007
28. ## math

identify all of the basic trig functions that fit each description. 1) is negative for angles in the 2nd and 4th quadrant 2) is unbounded answer: tan, cot 3) has a range of -1 ≤ y ≤ 1 answer: sin, cos are my answers correct? and i'm not sure what the

asked by stewie on October 9, 2015
29. ## trigonometry

Using exact values,find the value of: (A=30degrees) sin 2A + tan 3A/2 - cos A + sec(A+15), when A= 30degrees There were no parentheses and no exponents. please help by showing the work in details. Thank you! I pluged in the numbers and got this I don't

asked by alex on January 10, 2011
30. ## physics

Consider the state |ÏˆâŒª = âˆš2 |0âŒª + âˆš2 |1âŒª from the previous question. To estimate the phase Î¸, we measure |ÏˆâŒª in the sign basis. What is the probability that the outcome of the measurement is +? Recall that eiÎ¸ =

asked by JAY on February 18, 2013
31. ## Trigonometry

Suppose a smooth glass-top table is tilted slowly. The angle, A, at which a glass plate on the table begins to slide is 43º. Use the equation mg sin A = umg cos A to determine the coefficient of friction, u. A)0.43 B)0.22 C)0.90 D)0.93

asked by TeeKay on October 17, 2014
32. ## Trig calc

A) P is approximately (0.883, 0.469), is a point on the unit circle with angle 28 degrees estimate the following. Sin 152 degrees = Cos 152 degrees =

asked by Randy on October 23, 2014

Find sin(θ), cos(θ), tan(θ). Assume a = 40, b = 9, and c = 41. (Do not use mixed numbers in your answers.) Okay for some reason I keep getting this problem wrong. For sin(θ) I put 9/41, but it's wrong. Could someone please tell what I did wrong.

asked by Anonymous on December 13, 2010
34. ## Calculus

Hello, Could somebody kindly check my answer for the following question? Find the derivative of the following function: h(x)=3e^(sin(x+2)) h'(x)=3'(e^(sin(x+2))+3(e^(sin(x+2))' h'(x)=0(e^(sin(x+2))+3(e^(sin(x+2))(cos(1)) h'(x)=3cos1(e^(sin(x+2)) I would

asked by Constantine on August 18, 2015
35. ## calculus help

Find the points where the tangent line is horizontal or vertical. Find the area under one period of the curve. x= r(deta - cos deta) Y= r(1- sin deta)

asked by stan on August 26, 2010
36. ## Science: Physics

A force of 50 N directed at an angle of 45 degrees from the horizontal pulls a 70 kg sled across a frictionless pond. The acceleration of the sled is most nearly (sin 45 degrees = cos 45 degrees = 0.7).

37. ## math

What is the length of the vector [5 cos theta, 5 sin theta]? If the vector [5,0] is rotated 36 degrees in the counter clockwise direction, what are the components of the resulting vector?

asked by Sally on April 12, 2010
38. ## Math 30 Trig

For the equation 4 cos theta - sqrt12 =0, where 0< theta < or equal 2pi determine the measure of theta. One answer I got was 2pi/3, 4pi/3 and another time it totally different 5 pi/6, 7pi/6. Are either of these right if not HELP!

asked by Rae on March 10, 2010
39. ## Calculus: Differentiation

I am having trouble solving these. Could you explain how to do these 3 questions, step by step? That would be helpful! 1. Differentiate y=sin ^-1 (x^2) at x=0.5 . Round to 3 decimal points. 3. Differentiate y= (x^2 +1) tan ^-1 (x) at x=1 7. Differentiate

asked by Paige on December 6, 2018
40. ## Math

Calculate the integrals if they converge. 10.) Integral from 1 to infinity of X/4+X^2 dx 14.) integral from Pi/2 to Pi/4 of Sin X / sqrt cos x dx 22.) integral from 0 to 1 of ln x/x dx I'm having problems with working these out to figure out if they

asked by Jessica on April 21, 2008
41. ## Math: Parametric Equations

Let G be the graph of the parametric equations x = cos(4t), y = sin(6t). What is the length of the smallest interval P such that the graph of these equations for all t E P produces the entire graph G? (The "E" represents the symbol for "is in" that looks

asked by Katie on April 9, 2016
42. ## geometry

A private fence is to built around an 80m by 100m backyard. How many meters of fencing will be needed? If the private fence cos Php 550 per meter. What will be the cost of fence.?

asked by romilo on January 28, 2017
43. ## Maths

Solve the following questions (1) SinB=Cos35 degrees (2) Cos286 degrees (3) SinB=Cos3B (4) Cos2B=Sin3B (5) Cos y= Sin(y+22 degrees)

asked by Ande2 on February 3, 2019
44. ## Math homework help

Use half angle identities to find exact value. Given tan theta = -sqrt 2 / 2 and theta lies in quadrant IV, find cos theta / 2.

asked by Anonymous on May 7, 2014
45. ## Maths

Find all the values of theta between 0 degree and 360 degree, and state the quadrants in which they exist. (a)cos theta=-0.71 (b)tan theta=1.732

asked by Shane on April 5, 2013
46. ## Math

The graph of a trigonometric function oscillates between y=1 and y=-7. It reaches its maximum at x= pi and its minimum at x=3pi. which of the following could be the equation of the function? A) f(x)=4 cos x/2-3 B) f(x)=4 sin x/2-3 C) f(x)=4 sin 2x-3 D)

asked by Benji on March 7, 2018
47. ## Physics

a ball of mass 0.2 kg, initially at rest, is kicked directly toward a fence from a point 20m away. The velocity of the ball as it leaves the kicker's foot is 20m/s at angle of 40º above the horizontal ground. The top of the fence is 4m high. THe kicker's

asked by puff puff on September 17, 2006

Did I get this practice question right? 1. Consider the following functions: f(x)=cos(x^3-x) h(x)=|x-3|^3 g(x)=1n(|x|+3) s(x)=sin^3(x) Which of the following is true? (Points : 1) f is even, h and s are odd. ***f and g are even, s is odd. h and s are odd,

asked by Samantha on October 2, 2013
49. ## Math

Directions: Find the Location on Unit Circle, Period & General Solution for this problem>>>>>>> sin^2x=3cos^2x What I have so far: sin^2x=3cos^2 sin^2x/cos^2=3 tan^2x=3 tanx=+and- sqrt3

asked by Rachel on January 27, 2015
50. ## Calculus 3

A ball is thrown at an angle of 45 degrees to the ground. If the ball lands 90m away, what is the initial speed of the ball? I know you use x(t)=(v*cos(alpha))t and y(t)=(v*sin(alpha))t-g/2t^2 but I'm still really confused about what to do. Please show all

asked by Anonymous on February 26, 2012
51. ## trig

if sin23=p,write down the following in terms of P *cos113 *cos23 *sin46 so i draw the diagram an solve for x in terms of P an got 1-p so i don't know how to apply cos113and sin46 in terms of 23 or P but *cos 23 i wrote it as> 1-p/1 wch is 1-p

asked by onika on April 5, 2015
52. ## physics

A man is pulling on a rope with a force of 88N directed t an angle or 20 degrees to the horizontal. What is the x component of this force? What is the Y component of this force? Answer in units of N This is what i did, but i don't know if its right: x:

asked by alexa on July 2, 2011
53. ## Pre-Calculus

This question has me stuck. Use the Pythagorean identity sin^2 Θ + cos^2 Θ = 1 to derive the other Pythagorean identities, 1 + tan^2 Θ = sec^2 Θ and 1 + cot^2 Θ = csc^2 Θ. Discuss how to remember these identities and other fundamental identities.

asked by Iris on September 29, 2016
54. ## Math/Calculus

How would I integrate the following by parts: Integral of: (x^2)(sin (ax))dx, where a is any constant. Just like you did x^2 exp(x) below. Also partial integration is not the easiest way to do this integral. You can also use this method. Evaluate first:

asked by COFFEE on May 28, 2007
55. ## Algebra II

Find cos theta if sin theta = 3/5 and 90 degrees

asked by Lucy on April 19, 2008
56. ## 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
57. ## Math - Solving for Trig Equations

For the following equation, why cannot I not solve it? I keep getting an error. -- 2cosx - 3 = 0 -- I first isolated for "x" 2cosx-3 = 0 (2cosx/2) = (3/2) x = cos^-1(3/2) x = error? why? -- My textbook answer: 30 and 330 degrees --

asked by Anonymous on November 22, 2007
58. ## Math

Let G be the graph of the parametric equations x = cos(4t), y = sin(6t). What is the length of the smallest interval P such that the graph of these equations for all t E P produces the entire graph G?

asked by Bob on July 30, 2016
59. ## Precalculus

Let G be the graph of the parametric equations x=cos(4t)and y=sin(6t). What is the length of the smallest interval I such that the graph of these equations for all t in I produces the entire graph G?

asked by John on February 28, 2014
60. ## Precalculus

Let G be the graph of the parametric equations x=cos(4t)and y=sin(6t). What is the length of the smallest interval I such that the graph of these equations for all t in I produces the entire graph G?

asked by John on March 2, 2014
61. ## Calc.

Evaluate the definite integral. S b= sqrt(Pi) a= 0 xcos(x^2)dx I'm not sure if this is right? u= x^2 du= 2xdx du/2= xdx S (1/2)cos(u) S (1/2)*sin(x^2) [0.5 * sin(sqrt(Pi))^2] - [0.5 * sin(0)^2] 0 - 0 = 0, so zero is the answer?

asked by CMM on January 27, 2011
62. ## Calculus AB

I'm trying to find the second derivative of h(x)= x^2 + cos(kx) My answer for h'(x) is 2x - ksin(kx) but I'm not sure if that's right. Then the answer I got for h''(x) was h''(x) = 2 - k^2cos(kx) but I'm pretty sure that's wrong based on the graph I was

asked by Kris on May 6, 2012
63. ## Physic

The position of a mass on a spring is given by x = (7.6 cm) cos [2 π t / (0.82s)]. Where is the mass at t = 3.1 s? (Answer: 1.45cm) Answer is provided above. Please show all work on how to get the answer. Thank you.

asked by Anonymous on May 23, 2014
64. ## Physics

An airline pilot pulls her 12.0 kg rollaboard suitcase along the ground with a force of 25.0 N for 10.0 meters. The handle she pulls on makes an angle of 42.5 degrees with the horizontal. How much work does she do over the ten-meter distance? Tried doing:

asked by Riley on January 12, 2012
65. ## Trigonometry - Proofs

Prove that the average of the numbers n sin (n degrees) (n = 2, 4, 6, ... 180) is cot (1 degree) Hint: Express everything in terms of sin and cos. Can you rearrange the result into a form that allows you to use some of the identities you've learned? How to

asked by Sam on November 12, 2013
66. ## Math

[Multivariable Calc] Let R be the region that is inside of the cardioid r=2 + cos(theta) and outside the circle r=2? So i need to calculate the: *area of R, as well as *the volume above R and below plane z=12-3x *the density of that solid if the density

asked by Ryan on November 28, 2015
67. ## 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
68. ## trigonometry

x×sin^3A=y , cos^3A = sinA × cosA , x×sinA= y×cosA , then prove that x^2+ y^2= 1 I have no idea

asked by Venkatesh on March 23, 2016
69. ## antiderivatives

i need the antiderivative of sinxcosx dx for intergral pie/2 to 0 thanks. sin(x)cos(x)dx = sin(x)d[sin(x)] = 1/2d[sin^2(x)]

asked by andrew on January 18, 2007
70. ## trig

What is cos(11pi/3)? Explain your thinking. What is sin(13pi/4) ? Explain your thinking.

asked by BreAnne on January 27, 2012
71. ## trig

How do you solve for these identities: 1-sin^2è/cosè= cosè sin^4è-cos^4è=2sin^2è-1

asked by Anonymous on May 3, 2010
72. ## St Kabir

Find theta if sin(theta+36°)=cos theta where theta +36 is an acute angle

asked by Amrit on July 26, 2015
73. ## Math

The graph of r = 7/ (3 cos(theta) + 2 sin(theta)) is a line. What is the slope of the line? How do you do this!!!

asked by Joe on August 3, 2016
74. ## Precalculus

Find the exact value of cos(u+v) given that sine u=4/5 with u in quadrant II and sine v = -12/13 with v in quadrant IV. Not sure how to even begin.

asked by Reston on August 3, 2016
75. ## math help?!

If sin(Θ)=-5/8 and 180° < θ < 270°, what is the value of cos(θ)? −sqrt39/64 -sqrt39/8 **my answer sqrt39/64 sqrt39/8

asked by maple on May 16, 2017
76. ## trig

Verify the identity sin 3x cos 3x = 1/2 sin 6x can you show step by step please

asked by Ali on April 19, 2010
77. ## Math

Cos(-Θ) = Sqrt2/3 SinΘ

asked by Ashley on February 12, 2016
78. ## trig

sin(theta)cos(theta)sec(theta)csc(theta) How do I simplify

asked by stacey graham on May 5, 2010
79. ## calculus

Use the Table of Integrals to evaluate the integral. 0 to π ∫cos^6(θ) dθ I don't see anything like that on the table of integral. Need some help.

asked by Anonymous on March 10, 2019
80. ## Trigonometry.

Use the given information to evaluate cos (a-b). Cot a = 3/4, cot b = 24/25; pi

asked by Anonymous on May 6, 2014
81. ## Trigonometry

Sin A =1/2 and Cos B=12/13 where A lies in 1 quadrant and B lies in 3 quadrant. Then find tan(a-b).

asked by Jasmeet Singh on May 5, 2016
82. ## mathematics

Simplify the expressions 1.) Cos^2x/sin^2x + csc x sin x 2.) (Sec x +1)(sec x - 1)

asked by Tonie on October 8, 2011
83. ## trig

Given Tangent theta = -5 on 4 and cos theta >0, find sine theta and sec theta

asked by Ruby on June 4, 2011
84. ## Physics

In a game of pool the cue ball strikes another ball of the same mass and initially at rest. After the collision the cue ball moves at 3.50 m/s along a line making an angle of 22 degrees with its original direction of motion. and the second ball had a speed

asked by Nat on March 8, 2007
85. ## Math - Trig

For the equation 4 cos theta - square root 12 = 0, where 0 < theta < (or equal to) 2 pi, determine the measure of theta. The answers to choose from are: A) pi/ 3, 5 pi/ 3 B) 2 pi/ 3, 4 pi/ 3 C) 5 pi/ 6, 7 pi/ 6 D) pi/ 6, 11 pi/ 6 Please explain and show

asked by Angi on December 12, 2011
86. ## newton's law

A block of mass M is projected up a frictionless inclined plane with a speed VO. The angle of incline is given as theta. a. How far up the plane does it go? b. How much time does it take to get there? I was stuck after Fg(cos(theta+90)= Ma_x

asked by jack on October 13, 2012
87. ## MATH

The graph of a trigonometric function oscillates between y=1 and y=-7. It reaches its maximum at x= pi and its minimum at x=3pi. which of the following could be the equation of the function? A) f(x)=4 cos x/2-3 B) f(x)=4 sin x/2-3 C) f(x)=4 sin 2x-3 D)

asked by Benji on March 7, 2018
88. ## 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
89. ## MATH

The graph of a trigonometric function oscillates between y=1 and y=-7. It reaches its maximum at x= pi and its minimum at x=3pi. which of the following could be the equation of the function? A) f(x)=4 cos x/2-3 B) f(x)=4 sin x/2-3 C) f(x)=4 sin 2x-3 D)

asked by Benji on March 6, 2018
90. ## 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
91. ## CALCULUS - need help!

Determine the limit of the trigonometric function (if it exists). 1. lim sin x / 5x (x -> 0) 2. lim tan^2x / x (x ->0) 3. lim cos x tan x / x (x -> 0)

asked by ac on October 1, 2007
92. ## Math

determine the values of a,b,c,and d for a sinusoidal equation in the form: y= a sin b(x-c)+d and y= a cos b(x-c)+d using the max= 23.1 and min= -19.7 to determine the value. how to determine the values? thank you..

asked by EKA on October 27, 2014
93. ## Trigonometry (identities)

Simplify: 1. sin(α+β)+sin(α-β) 2. (-8cosxsinx+4cos2x)^2 + (4cos^2x+8sinxcosx)^2 3. sqrt(sin^4xcosx) * sqrt(cos^3x)

asked by Anna on March 31, 2015
94. ## trig

in proving trigonometric identities if 1 + sin^2 theta is equal to 2 sin^2 theta + cos^2 theta. what is the correct answer?

asked by mien on February 1, 2012
95. ## calculus

what is the integral of {sin(x)tan(x)} i tried turning tan(x) into sin(x)/cos(x) then doing u substitutions but i always have an extra sin(x) left. can you help me pleeeease

asked by mo on September 28, 2011
96. ## TRIGONOMETRY

Write the following trigonometric expression as an algebraic expression in x free of trigonometric or inverse trigonometric functions sin(cos^-1 x) -1≤x≤1

asked by Matthew on December 4, 2012
97. ## Algebra II Part 2

The equation h=7 cos{pi/3 t} models the height h in centimetres after t seconds of a weight attached to the end of a spring that has been stretched and then released. Find the times at which the weight is at a height of 1 cm,of 3 cm,and of 5 cm below the

asked by Karen on May 18, 2013
98. ## algebra II Part 2

The equation h=7 cos{pi/3 t} models the height h in centimeters after t seconds of a weight attached to the end of a spring that has been stretched an then released. (C).Find the times at which the weight is at a height of 1 cm,of 3 cm,and of 5 cm below

asked by Karen on May 19, 2013
99. ## Calculus

Alright, I want to see if I understand the language of these two problems and their solutions. It asks: If F(x) = [given integrand], find the derivative F'(x). So is F(x) just our function, and F'(x) our antiderivative? 1) F(x) = ∫(2, x)

asked by Justin on November 4, 2015
100. ## math

Question Part Points Submissions Used Verify that the function satisfies the three hypotheses of Rolle's Theorem on the given interval. Then find all numbers c that satisfy the conclusion of Rolle's Theorem. (Enter your answers as a comma-separated list.)

asked by joe on October 17, 2012