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

4,795 questions, page 22-
## Trigonometry

Γ is the circumcircle of triangle ABC with radius 12√2. If 9cos(∠B+∠C)cos∠A=−1, what is the value of BC?

*asked by Shin on May 21, 2013* -
## Math

verify: sin^3 x - cos^3 x = (sinx+cosx)(1-sinxcosx)

*asked by Anonymous on January 25, 2011* -
## MATHS - URGENT

Write the expression in terms of sine only. 8(sin 2x − cos 2x)

*asked by Shane on May 21, 2013* -
## pre-cal

verify the identity... cot(-a)cos(-a)+sin(-a)=-csc(a)

*asked by Anonymous on February 2, 2011* -
## maths

dy/dt = -t^3y^2-ty^2 dx/dt=(sin t)/(cos t+10) dy/dx -3y/x =x^3cosx Which differential method should be used for each equation?

*asked by s17 on March 2, 2017* -
## Opt math URGENT

prove that : cos^3(θ)sin^2(θ)=1/16[2cos(θ)-3cos(θ)-5cos(θ)]

*asked by Rabin on August 9, 2016* -
## math 12

Could you please show me how to solve this question.If 2 cos A-1=0, where 0< or = A < 2pi what is A equal to?

*asked by Tori on March 19, 2010* -
## Pre Calculus

Verify the identity: cos x + sin x tan x = sec x.

*asked by Kim on March 23, 2011* -
## Math

Evaluate the identity (cos^2x-sin^2x)/(1-tan^2x)=cosx^2X

*asked by Katelyn on March 30, 2011* -
## trig

How do you solve cos(2arcsin 1/4) using inverse trig. functions??!! PLEASE HELP ME!

*asked by Tor on May 9, 2011* -
## trig

find sin if cos(2è)=(4)/(5) and theta terminates in quadrant 1

*asked by Anonymous on May 9, 2011* -
## Pre-Calc

cos^3 = (1/2 cosx)(1+cos2x) Please make the left match the right.

*asked by Amy on January 24, 2018* -
## Math

Rewrite in terms of an expression containing only cosines to the power 1. 4 cos^6x

*asked by Sarah on March 17, 2013* -
## calculus

Use the Table of Integrals to evaluate the integral (x sine(6x^2)cos(7x^2)dx)

*asked by ali on February 14, 2010* -
## Trig

Rewrite cos(tan^-1(v)) as an algebraic expression in v. Can someone help me with this problem? Thanks

*asked by Jennifer on May 15, 2011* -
## calculus

find the lim cos 2x/(5 + x) as x approaches pos. inifinity

*asked by dee on February 14, 2010* -
## Math

Transform to a Cartesian Equation: a. x = sin t y = cos t b. x = t^(1/3) -1 y = t^2 - t --- This is what I have for B so far: y = t(t-1) t = (x+1)^3 y = (x+1)^3[(x+1)^3-1] = (x^3 + 3x^2 + 3x + 1)[x^3+3x^2+3x] ...??? and IDK about A. Help? Thank you so

*asked by Anonymous on February 11, 2010* -
## math (differential equation)

show that y sub n=cos(ncos^-1(x)) satisfies the differential equation: (1-x^2)(d^2y/dx^2)-x(dy/dx)+n^2(dy/dx)=0

*asked by shoosh on March 3, 2013* -
## math

f(t) = \int_0^t \frac{x^2+11 x+24}{ 1+\cos^2(x)} dx At what value of t does the local max of f(t) occur? t = ?

*asked by Anonymous on June 29, 2015* -
## maths

how can i find a general solution of g(x)when they give me g(X) =cos (x+30)and g(X)= -2sinx

*asked by mazandie Magaduzela on March 26, 2013* -
## Math

A simplified version of the expression 2sinθ (cos θ)(cotθ) is

*asked by TeeKay on October 13, 2014* -
## precalculus

find the exact value: cos^-1 (square root of 2 divided by 2)

*asked by john 2020 on March 8, 2010* -
## math

In triangle ABC if

*asked by ashley on April 18, 2011* -
## math

In triangle ABC if

*asked by ashely on April 18, 2011* -
## Algebra 1

In triangle ABC ,if

*asked by Maram on April 19, 2011* -
## math

In triangle ABC ,if

*asked by Maram on April 19, 2011* -
## math

how do I find the sin, cos, and tan of -60 degrees without using a calculator?

*asked by chris on December 14, 2008* -
## maths period help

find the period cos(theta/4) step plz

*asked by weryiyemi on March 18, 2017* -
## trig help

verify that cos(A-B)/cosAsinB=tanA+cotB is an identity

*asked by sam on April 14, 2008* -
## trigonometry

How to verify this identity: 1+ tan x (over) = secant x sine x + cos x

*asked by Debi on February 24, 2010* -
## math

find the sum cos^2(j) + sin^2(j), if j = p/3 -do I have to use a pythagorean identity?

*asked by Matt on January 24, 2016* -
## pleeaasee hellpp!!

if sin A= the square root of eleven over 7, find the value of cos 2A.

*asked by Please Answer :) on May 26, 2010* -
## Trigonometry

evaluate cot 2x = 5/12 with 0

*asked by David on November 28, 2013* -
## trig

find cos(θ)ˏsin(θ)ˏtan(θ), if cot (2θ)=5/12 with 0≤2θ≤π Answer this Que

*asked by Anonymous on November 27, 2013* -
## Math Analysis

Find the exact value of cos(x/2) if sin x = 3/4 and x is in quadrant II. ==> I got ã(4-ã7)/2. Is this correct?

*asked by Emily on May 3, 2010* -
## Maths

Solve for x: 5sin(2x) + cos(x) = -1.916 Can someone please show me the steps?

*asked by Claire on October 17, 2010* -
## math

verify, 1+csc - 0 ---------- = sec0 cos(-0)+cot(-0) 0 is angle.

*asked by am on October 17, 2010* -
## Trigonometry

Prove that (3cos^2x + 8sinx-8/cos^2x) = (3sinx-5/sinx+1)

*asked by Trig on November 9, 2008* -
## math !!

solve the equation for the interval 0

*asked by Amy on September 6, 2008* -
## math

Use logarithmic differentiation to find the derivative of the function. y = (cos 2x)x

*asked by mat on April 5, 2014* -
## 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* -
## calculus

Prove that cos(sin inverse x) = square root ( 1-x^2)

*asked by Samantha on September 29, 2010* -
## calculus

Prove that cos(sin inverse x) = square root ( 1-x^2)

*asked by Samantha on September 29, 2010* -
## Calculus

Find the derivative. g(x)=cos(x^6) Isn't the answer -6xsin(x^6)

*asked by George on September 27, 2008* -
## Trig

given that sinx=3/4 and cosy=-5/13 and both x and y are in quadrant II, find the exact value of cos(x-y)

*asked by Blaire on March 2, 2014* -
## Math

Given cot u=2/5 and cos v=-3/5 find tan(u+v) assume 0

*asked by Blaire on March 2, 2014* -
## Physics, math

What is the answer to this? I don't understand how to solve it. 1.2 = 4.6 tan 50 - 4.9 (4.6^2)/(x^2 cos^2 50)

*asked by Taylor on September 27, 2015* -
## Calculus

Can someone help me to integrate by substitution the indefinite integral: (sinx)/ (1+cos(^2)x)?

*asked by Em on July 24, 2010* -
## Calculus

(sin(47))^2 + (cos(43))^2 = With the correct number of significant figures.

*asked by jim on August 24, 2010* -
## maths trigonometry

Expand the following using compound angle formulae Sin(m-n) Cos(p-55)

*asked by amanda on January 16, 2017* -
## Math

f(x) = cos(x) + 3x Find f^-1 (1) and (f^-1)' (1) f^-1 (1) = 0 (f^-1)' (1) = 1/3 These are the answers given, but I also don't understand how my teacher got these.

*asked by Dave on December 5, 2016* -
## Math

Simplify the expression csc@cos@tan@. What is the best way to solve this?

*asked by V on September 5, 2010* -
## Math

Solve this multiple-angle equation. cos x/2 = -(sqrt3)/2

*asked by Anonymous on October 18, 2015* -
## Calculus

Find dy / dx by implicit differentiation. 2sin(9x)cos(3y)=3 dy/dx=_____

*asked by Starfallen on October 25, 2010* -
## Trig

If sec A =5/4 and A is an angle in Quadrant IV, find the value of cos A. A. -4/5 B.4/5 C.-5/4 Is it choice A

*asked by Kiki on April 26, 2014* -
## Trignometry

Write the complex number in the form a=bi √(3)(cos π/3 + isin π/3)

*asked by yes on July 2, 2013* -
## Calculus

show the following linearization of the function f(x)=cos(3x)-3sin(3x) at x=2pi

*asked by Jay on April 7, 2010* -
## trig, math

Which of these functions has period 7? A)y= cot 7/pi x B)y= tan pi/7 x C)y= sin 7/pi x D)y= cos pi/7 x

*asked by John on July 1, 2013* -
## Calculus

Find the equation of the tangent line to f(x)=sec x - 2 cos x at (pi/3, 1).

*asked by Anonymous on August 30, 2015* -
## Calculus

prove if an identity csc (x)-cot (x)=sin (x)/1+cos(x)

*asked by Anonymous on October 15, 2018* -
## Trig

Determine the frequency of y = 2 - 3 cos 10x. (nearest tenth) Please help

*asked by Kay on December 31, 2010* -
## Math Trigonometry

Given w=2+2i and v=−5√3+5i, vw^2 can be expressed as r*(cos(α∘)+i*sin(α∘)), where r is a real number and 0≤α≤360. What is the value of r+α?

*asked by Crow on June 21, 2013* -
## trig

Find all real numbers in [0, 2π) that satisfy the equation. cos 2x = √(2)/2

*asked by tony on June 17, 2013* -
## trig

Given that cos A = 5/13 and A and B are both acute angles, calculate the value of Sin2A and Cos2A

*asked by uche on June 6, 2014* -
## trig

simplify the expression. (sin^2x+cos^2x) - (csc^2x-cot^2x)

*asked by trig on July 14, 2013* -
## trig

simplify the expression. cos^2x+sin^2x/cot^2x-csc^2x

*asked by tony on July 14, 2013* -
## Algebra 2

Find the period and the amplitude of the periodic function. y=-4 cos 8x

*asked by Austin on May 19, 2014* -
## Math

The point (5,-2) in on the terminal side of an angle t. Find cos

*asked by Brandon on November 16, 2016* -
## calculus

Find the derivative r '(t) of the vector function r(t).

*asked by Mike on April 20, 2010* -
## Trigonometry

Solve the following equation tan (2x)+ sec (2x) = cos (x)+ sin (x) Thanks for your help

*asked by Tommy on July 24, 2008* -
## PreCalc

Verify the Identity. cos^4xcsc^2x = csc^2x + som^2x - 2

*asked by Brit on November 1, 2017* -
## calculus help

find the derivative of the function. integral cos(x) to sin(x) ((ln(8+3v))dv)

*asked by Kevin on May 1, 2014* -
## Trigonometry

Prove the identity. 6cos^2(x)-1 -12cos^4(x) +8cos^6(x)= cos^3(2x) Thanks for your help :)

*asked by Tommy on July 18, 2008* -
## Math

If x is an angle in the first quadrant and cscx = 3 find the exact value of cos 2x

*asked by Nicole on April 15, 2010* -
## precalc

solve in degrees 1) 2sin2 (x/4) = 1 2) 2 cos (3x) + 1 = 0 3) cot2 (x + 18°) = 1 4) (1 + tan(x + 87°)) / 2 = 7

*asked by yani on October 27, 2015* -
## 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* -
## Trigonometry

Verify the identity: cos x + sin x tan x = sec x.

*asked by CJ on January 13, 2011* -
## trig

if cos(theta) equal -3/4 find sin(2theta)

*asked by Anonymous on September 1, 2011* -
## pre cal

show that 6+6sin X is equivakent to --------- - 7 cos x 6cos x ------------ -7(1- sin x)

*asked by colleen on February 16, 2009* -
## Math

use the unit circle to prove that tan(x/2) = (sin(x))/(1+cos(x))

*asked by Zack on December 12, 2012* -
## math

how do I do this? I think I have to simplify it? (sin^2ө + cos^3ө/sinө + cosө)+ sinөcosө

*asked by maggie on February 12, 2009* -
## Math

y = 4 cos (3/4) θ a. amplitude = 4 b. number of cycles = ? c. period = (8pi/3)

*asked by Anonymous on May 25, 2018* -
## calculus - identities

prove this identity: sec(y) - cos(y)= tan(y)sin(y) THANK YOU!!

*asked by Amber on October 16, 2009* -
## Calculus

maximum and minimum of y = cos(x) + sin (x)on the interval [0,2pi]

*asked by Mark on October 25, 2009* -
## amth

Solve the multiple-angle equation. cos x/2 = - squareroot 3/2

*asked by elise on July 11, 2016* -
## calculus

find the derivative of y=cos pix/sinpix+cospix

*asked by vicki on October 9, 2011* -
## Pre Calculus

Find the exact value ofcos (u+v) given that sin u= 7/25 and cos v=−12/13. (Both u and v are in Quadrant II.)

*asked by Jessica Maths on July 11, 2016* -
## trig, precalc, math, algebra, trigonometry

Rewrite: tan(cos^−1 (v)) as an algebraic expression in v. Please help me understand.

*asked by Veronica on May 5, 2016* -
## calculus-derivatives

y=cos^3(12theta) find derivative using chain rule

*asked by hailey on September 27, 2011* -
## maths

Express sin 2x cos 4x as a sum of trigonometric functions

*asked by tom on December 24, 2012* -
## maths

Express sin 2x cos 4x as a sum of trigonometric functions.

*asked by laura on December 23, 2012* -
## Calculus

Which of the following functions does not have a derivative of zero? A. y=-1/100 B. y=4(pi)^2-9 C. y=sin^2x+cos^2x D. y=cscxtanxcosx E. All do

*asked by Anonymous on December 1, 2014* -
## Calc

find F''(pi/3) f(x)= 4cos(x/2) i got -cos(pi/6) but i don't think that's the correct answer... Thanks!

*asked by Lilly on September 11, 2011* -
## TRIG

THE SIN COS SEC TAN COT CSC 5X+Y=0

*asked by NAUDIA on September 20, 2011* -
## trig

Use a half-angle formula to find the exact value of cos 5ð/12

*asked by Steve on December 16, 2009* -
## Trigonometry

Prove that sin(n+1)Asin(n+2)A + cos(n+1)Acos(n+2)A = cosA

*asked by Kewal on December 30, 2011* -
## Trigonometry

Prove that sin(n+1)Asin(n-1)A + cos(n+1)Acos(n-1)A = cos2A

*asked by Kewal on December 30, 2011* -
## calculus

Find any critical numbers of the function h(x)=sin^2(x)+cos(x) 0 < x < 2π

*asked by Anonymous on October 30, 2012* -
## trig

cos t=.7, tan t

*asked by Marni on November 27, 2011* -
## Trig

Find all real numbers that satisfy the equation. 2 cos x + 1 = 0

*asked by Anonymous on November 1, 2011*