Thursday

September 3, 2015
Number of results: 7,677

**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 64degrees 6' 45'' h. cos...
*January 1, 2011 by Anon*

**verifying identities**

how do you veriy tan x + Cot y -------------- = tan y + cot x 1-tan x cot y sin^4x + cos^4x = 1- 2cos^2x + 2cos^4
*July 22, 2008 by Dizzytrig*

**Pre-Calculus**

I don't understand,please be clear! Prove that each equation is an identity. I tried to do the problems, but I am stuck. 1. cos^4 t-sin^4 t=1-2sin^2 t 2. 1/cos s= csc^2 s - csc s cot s 3. (cos x/ sec x -1)- (cos x/ tan^2x)=cot^2 x 4. sin^3 z cos^2 z= sin^3 z - sin^5 z
*October 31, 2013 by Anonymous*

**Pre-Calculus**

Prove that each equation is an identity. I tried to do the problems, but I am stuck. 1. cos^4 t-sin^4 t=1-2sin^2 t 2. 1/cos s= csc^2 s - csc s cot s 3. (cos x/ sec x -1)- (cos x/ tan^2x)=cot^2 x 4. sin^3 z cos^2 z= sin^3 z - sin^5 z
*October 31, 2013 by Anonymous*

**precalculus**

For each of the following determine whether or not it is an identity and prove your result. a. cos(x)sec(x)-sin^2(x)=cos^2(x) b. tan(x+(pi/4))= (tan(x)+1)/(1-tan(x)) c. (cos(x+y))/(cos(x-y))= (1-tan(x)tan(y))/(1+tan(x)tan(y)) d. (tan(x)+sin(x))/(1+cos(x))=tan(x) e. (sin(x-y...
*April 14, 2013 by anonymous*

**trig**

I do not understand these problems. :S I'd really appreciate the help. Use trigonometric identities to transform the left side of the equation into the right side. cot O sin O = cos O sin^2 O - cos^2O = 2sin^2 O -1 (tan O + cot O)/tan O = csc^2 O
*April 27, 2009 by Matt*

**Math - Solving Trig Equations**

What am I doing wrong? Equation: sin2x = 2cos2x Answers: 90 and 270 .... My Work: 2sin(x)cos(x) = 2cos(2x) sin(x) cos(x) = cos(2x) sin(x) cos(x) = 2cos^2(x) - 1 cos(x) (+/-)\sqrt{1 - cos^2(x)} = 2cos^2(x) - 1 cos^2(x)(1 - cos^2(x)) = 4cos^4(x) - 4cos^2(x) + 1 5cos^4(x) - 5cos^...
*November 24, 2007 by Anonymous*

**algebra**

Can someone please help me do this problem? That would be great! Simplify the expression: sin theta + cos theta * cot theta I'll use A for theta. Cot A = sin A / cos A Therefore: sin A + (cos A * sin A / cos A) = sin A + sin A = 2 sin A I hope this will help. in my algebra ...
*February 18, 2007 by Valerie*

**trig**

please help me with some questions I skipped on a review for our test coming up? solve 5-7 on the interval 0 greater than or equal to x less than or equal to 2pi. 5. sin x=sqrt3/2 6. cos x=-1/2 7. tan x=0 ---------------- 14. what is the exact value of tan[arcsin(.43...
*February 22, 2012 by BreAnne*

**Calc**

Which expression is equivalent to sin(3x) + sin x? A. 2cos(2x)sin x B. 2sin(2x)sin x C. -2sin(2x)cos x D. 2sin(2x)cos x E. -2cos(2x)sin x
*April 18, 2013 by Chris*

**Math**

Which expression is equivalent to sin(3x) + sin x? A) 2cos(2x)sin x B) 2sin(2x)sin x C) -2sin(2x)cos x D) 2sin(2x)cos x E) -2cos(2x)sin x
*March 24, 2014 by Anonymous*

**Math, derivatives**

f(x) = x² + 2Cos²x, find f ' (x) a) 2(x+cos x) b) x - sin x c) 2x + sin x d)2(x - sin2x) I got neither of these answers, since the 2nd part should be chain rule, right? f(x) = x² + 2Cos²x = x² + 2(Cos x)² then f '(x) = (2)(2)(cosx)(-sinx) My answer: f '(x) = 2x - 4cosxsinx If ...
*May 5, 2008 by Terry*

**Trigonometry**

1.Solve tan^2x + tan x – 1 = 0 for the principal value(s) to two decimal places. 6.Prove that tan y cos^2 y + sin^2y/sin y = cos y + sin y 10.Prove that 1+tanθ/1-tanθ = sec^2θ+2tanθ/1-tan^2θ 17.Prove that sin^2w-cos^2w/tan w sin w + cos w tan w = cos ...
*January 1, 2013 by Alonso*

**Trig**

Given: cos u = 3/5; 0 < u < pi/2 cos v = 5/13; 3pi/2 < v < 2pi Find: sin (v + u) cos (v - u) tan (v + u) First compute or list the cosine and sine of both u and v. Then use the combination rules sin (v + u) = sin u cos v + cos v sin u. cos (v - u) = cos u cos v + ...
*December 29, 2006 by Nan*

**Pre-calc/Calc**

Which expression is equivalent to sin(3x) + sin x? A. 2cos(2x)sin x B. 2sin(2x)sin x C. -2sin(2x)cos x D. 2sin(2x)cos x E. -2cos(2x)sin x
*April 17, 2013 by Chris Math Hw Help*

**Math**

Which of the following are inverse functions? 1. Arcsin x and sin x 2. cos^-1 x and cos x 3. csc x and sin x 4. e^x and ln x 5. x^2 and +/- sqrt x 6. x^3 and cubic root of x 7. cot x and tan x 8. sin x and cos x 9. log x/3 and 3^x I believe the answers are 2, 4, 6, and 9, but ...
*April 16, 2009 by Anonymous*

**math (repost)**

Which of the following are inverse functions? 1. Arcsin x and sin x 2. cos^-1 x and cos x 3. csc x and sin x 4. e^x and ln x 5. x^2 and +/- sqrt x 6. x^3 and cubic root of x 7. cot x and tan x 8. sin x and cos x 9. log x/3 and 3^x I believe the answers are 2, 4, 6, and 9, but ...
*April 16, 2009 by Anonymous*

**Calc**

Which functions of x and y in terms of time t can be derived from this rectangular equation? (x^2/4)+y^2=1 A. x = 2sin t, y = -cos t B. x = sin t, y = 5cos t C. x = sin t, y = 2cos t D. x = -sin t, y = 2cos t E. x = 2sin t, y = 5cos t
*April 26, 2013 by Chris*

**Math**

Prove each identity: a) 1-cos^2x=tan^2xcos^2x b) cos^2x + 2sin^2x-1 = sin^2x I also tried a question on my own: tan^2x = (1 – cos^2x)/cos^2x R.S.= sin^2x/cos^2x I know that the Pythagorean for that is sin^2x + cos^2x That's all I could do.
*July 18, 2011 by Kate*

**verifying trigonometric identities**

How do I do these problems? Verify the identity. a= alpha, b=beta, t= theta 1. (1 + sin a) (1 - sin a)= cos^2a 2. cos^2b - sin^2b = 2cos^2b - 1 3. sin^2a - sin^4a = cos^2a - cos^4a 4. (csc^2 t / cot t) = csc t sec t 5. (cot^2 t / csc t) = csc t = sin t
*March 3, 2008 by Anonymous*

**Trig.......**

I need to prove that the following is true. Thanks (2tanx /1-tan^x)+(1/2cos^2x-1)= (cosx+sinx)/(cosx - sinx) and thanks ........... check your typing. I tried 30º, the two sides are not equal, they differ by 1 oh , thank you Mr Reiny I'll tell my teacher this Question is Wrong...
*April 18, 2007 by abdo*

**TRIG..............**

Q.1 Prove the following identities:- (i) tan^3x/1+tan^2x + cot^3x/1+cot^2 = 1-2sin^x cos^x/sinx cosx (ii) (1+cotx+tanx)(sinx-cosx)/sec^3x-cosec^3x = sin^2xcos^2x.
*June 10, 2011 by MATHS*

**TRIGONOMETRY *(MATHS)**

Q.1 Prove the following identities:- (i) tan^3x/1+tan^2x + cot^3x/1+cot^2 = 1-2sin^x cos^x/sinx cosx (ii) (1+cotx+tanx)(sinx-cosx)/sec^3x-cosec^3x = sin^2xcos^2x.
*June 9, 2011 by MATH...............*

**Trig Identities**

Proving identities: 1) 1+ 1/tan^2x = 1/sin^2x 2) 2sin^2 x-1 = sin^2x - cos^2x 3) 1/cosx - cosx = sin x tan x 4) sin x + tan x =tan x (1+cos x) 5) 1/1-sin^2x= 1+tan^2 x How in the world do I prove this...please help... I appreciateyour time thankyou soo much!!
*February 17, 2013 by Deepa*

**Pre-calculus help**

I have two problems I am stuck on, if you could show me how to solve the problems it would be much appreciated. 1) Find sin 2x, cos 2x, and tan 2x from the given information. tan x = − 1/6, cos x > 0 sin 2x = cos 2x = tan 2x = 2) Find sin 2x, cos 2x, and tan 2x from ...
*April 10, 2015 by Holly*

**trigonometry repost**

Reduce (csc^2 x - sec^2 X) to an expression containing only tan x. (is this correct?) csc x = 1/sin x sec x = 1/cos x tan x = 1/cot x sin^2 x + cos^2 x = 1 1 + cot^2 x = csc^2 x tan^2 x + 1 = sec^2 x csc^2 x - sec^2 x = 1 + cot^2 x - (1 + tan^2 x) = cot^2 x - tan^2 x = (1/tan^...
*February 1, 2011 by Anonymous*

**Mathematics - Trigonometric Identities**

Let y represent theta Prove: 1 + 1/tan^2y = 1/sin^2y My Answer: LS: = 1 + 1/tan^2y = (sin^2y + cos^2y) + 1 /(sin^2y/cos^2y) = (sin^2y + cos^2y) + 1 x (cos^2y/sin^2y) = (sin^2y + cos^2y) + (sin^2y + cos^2y) (cos^2y/sin^2y) = (sin^2y + cos^2y) + (sin^2y + cos^2y)(sin^2y) / (sin^...
*November 8, 2007 by Anonymous*

**Precalculus**

Verify the identities. Cos^2x - sin^2x = 2cos^2x - 1 When verifying identities, can I work on both side? Ex. 1 - sin^2x - sin^2x = 1 - 2sin^2x 1 - 2sin^2x = 1 - 2sin^2x
*April 3, 2013 by Shadow*

**math**

Simplify the trigonometric function sin^4x-cos^4x cos^2â-sin^2â=1+2cosâ (1+cot^2x )(cos^2x )=cot^2x cot^2t/csct =(1-sin^2t)/sint (Work on both sides!) sinècscè- sin^2è=cos^2è
*June 4, 2015 by Anonymous*

**trigonometry hlp me**

6.Prove that tan y cos^2 y + sin^2y/sin y = cos y + sin y 10.Prove that 1+tanθ/1-tanθ = sec^2θ+2tanθ/1-tan^2θ 17.Prove that sin^2w-cos^2w/tan w sin w + cos w tan w = cos w-cot w cos w 23.Find a counterexample to shows that the equation sec a – cos a...
*January 2, 2013 by eddy*

**Precal**

I do not understand how to do this problem ((sin^3 A + cos^3 A)/(sin A + cos A) ) = 1 - sin A cos A note that all the trig terms are closed right after there A's example sin A cos A = sin (A) cos (A) I wrote it out like this 0 = - sin^6 A - cos^6 A + 2sin^3 A cos^3 A - 2sin^3 ...
*January 14, 2010 by Joe*

**Math (Trig)**

sorry, another I can't figure out Show that (1-cot^2x)/(tan^2x-1)=cot^2x I started by factoring both as difference of squares. Would I be better served by writing in terms of sine and cosine? Such as: [1-(cos^2x/sin^2x)]/[(sin^2x/cos^2x)-1]=(cos^2x/sin^2x)
*April 9, 2008 by mtd*

**trigonometry...........**

Prove the following identity:- (i) tan^3x/1+tan^2x + cot^3x/1+cot^2 = 1-2sin^x cos^x/sinx cosx
*June 11, 2011 by MATHS*

**tigonometry**

expres the following as sums and differences of sines or cosines cos8t * sin2t sin(a+b) = sin(a)cos(b) + cos(a)sin(b) replacing by by -b and using that cos(-b)= cos(b) sin(-b)= -sin(b) gives: sin(a-b) = sin(a)cos(b) - cos(a)sin(b) Add the two equations: sin(a+b) + sin(a-b) = ...
*November 26, 2006 by Pablo*

**trig**

For each expression in column I, choose the expression from column II to complete an identity: Column I Column II 1. -tanxcosx A. sin^2x/cos^2x 2. sec^2x-1 B. 1/sec^2x 3. sec x/cscx C. sin(-x) 4. 1+sin^2x D.csc^2x-cot^2x+sin^2x 5. cos^2 x E. tanx I figured #1 is C, #2 is A, ...
*March 19, 2011 by gin*

**trig 26**

simplify to a constant or trig func. 1. sec ²u-tan ²u/cos ²v+sin ²v change expression to only sines and cosines. then to a basic trig function. 2. sin(theta) - tan(theta)*cos(theta)+ cos(pi/2 - theta) 3. (sec y - tan y)(sec y + tan y)/ sec y combine fractions and simplify to a...
*March 14, 2010 by hilde*

**trig**

it says to verify the following identity, working only on one side: cotx+tanx=cscx*secx Work the left side. cot x + tan x = cos x/sin x + sin x/cos x = (cos^2 x +sin^2x)/(sin x cos x) = 1/(sin x cos x) = 1/sin x * 1/cos x You're almost there. thanks so much! i could not figure...
*May 7, 2007 by Devon*

**Math - Trig**

I'm trying to verify these trigonometric identities. 1. 1 / [sec(x) * tan(x)] = csc(x) - sin(x) 2. csc(x) - sin(x) = cos(x) * cot(x) 3. 1/tan(x) + 1/cot(x) = tan(x) + cot(x) 4. csc(-x)/sec(-x) = -cot(x)
*September 21, 2009 by Liath*

**Trigonometry**

Verify the identities. 1.) √1-COSθ/1+COSθ= 1+SINθ/SINθ 2.) SEC X SIN(π/2-X)= 1 3.) CSC X(CSC X-SIN X)+SIN X-COS X/SIN X + COT X= CSC²X 4.) CSC^4 X-2 CSC²X+1= COT^4 X 5.) CSC^4 θ-COT^4 θ= 2 CSC²θ-1 6.) TAN^5 X= TAN³X SEC²X-TAN³X 7...
*February 17, 2013 by AwesomeGuy*

**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<alpha<180, and 90<beta<180. My answer: -33/56 Which expression is ...
*April 22, 2009 by Patrick*

**Trigonometry desperate help, clueless girl here **

2. solve cos 2x-3sin x cos 2x=0 for the principal values to two decimal places. 3. solve tan^2 + tan x-1= 0 for the principal values to two decimal places. 4. Prove that tan^2(x) -1 + cos^2(x) = tan^2(x) sin^2 (x). 5.Prove that tan(x) sin(x) + cos(x)= sec(x) 6.Prove that tan(x...
*August 16, 2013 by Suzy*

**trignonmetry**

6. Prove that tan λ cos^2 λ + sin^2λ/sin λ = cos λ + sin λ 10. Prove that 1+tanθ/1-tanθ = sec^2θ+2tanθ/1-tan^2θ 17.Prove that sin^2w-cos^2w/tan w sin w + cos w tan w = cos w-cot w cos w 23. Find a counterexample to shows...
*December 16, 2012 by yoshi*

**Trigonometry**

Prove the following trigonometric identities. please give a detailed answer because I don't understand this at all. a. sin(x)tan(x)=cos(x)/cot^2 (x) b. (1+tanx)^2=sec^2 (x)+2tan(x) c. 1/sin(x) + 1/cos(x) = (cosx+sinx)(secx)(cscx) d. tan^2 (x)(1+1/tan^2 x) = 1/(1-sin^2x) e. sin...
*November 24, 2013 by Jessy*

**Math(Please help)**

1)tan Q = -3/4 Find cosQ -3^2 + 4^2 = x^2 9+16 = sqrt 25 = 5 cos = ad/hy = -4/5 Am I correct? 2) Use the sum and difference identites sin[x + pi/4] + sin[x-pi/4] = -1 sinx cospi/4 + cosxsin pi/4 + sinx cos pi/4 - cosx sin pi/4 = -1 2 sin x cos pi/4 =-1 cos pi/4 = sqr2/2 2sin^x...
*March 16, 2010 by Abbey*

**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 - cosx = 0 4. cos 4x = sin...
*March 3, 2011 by anon*

**trig**

Show that 1-cos2A/Cos^2*A = tan^2*A 1-cos2A/Cos^2*A = [Cos^2(A) - Cos(2A)]/Cos^2(A). Substitute: Cos(2A) = 2Cos^2(A) - 1: [1 - Cos^2(A)]/Cos^2(A)= Sin^2(A)/Cos^2(A) = tan^2(A)
*November 26, 2006 by Paul C*

**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 = tan2 sin2 . 5. Prove ...
*August 16, 2013 by suzy *

**math**

There are no typos and no work b/c I don't know how to do them. Thanks. 1)Find cos theta if sin theta=3/5 and 90 degrees<theta<180 degrees. A)4/5 B)-4/5 C)square root of 34/5 D)-square root of 34/5 I chose A 2)Simplify:1-csc^2theta/cot^2theta A)-1 B)1 C)tan^2theta D)1/...
*February 14, 2008 by Jon*

**precalculus**

I dont understand this problem: (Tanө + cos ө)/ (sec ө + cot ө) so I start off like this: ={(sinө / cos ө)+cosө}{cos ө + (sinө/cosө)} =[(sin ө +cos^2ө) (cos^2ө +sin ө)]/ cos ө but what ...
*February 22, 2009 by allison*

**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))
*June 9, 2011 by HotMath*

**Math**

1)Find cos theta if sin theta=3/5 and 90 degrees<theta<180 degrees. A)4/5 B)-4/5 C)square root of 34/5 D)-square root of 34/5 I chose A 2)Simplify:1-csc^2theta/cot^2theta A)-1 B)1 C)tan^2theta D)1/sin^4theta I chose C 3)Simplify:-5(cot^2theta-csc^2theta) A)5 B)-5 C)-5csc...
*February 13, 2008 by Jon*

**Algebra II**

Which of the following expressions are not equal to 1? A) sin^2 theta + cot^2 theta sin^2 theta B) (sin^2 theta/1-cos theta)-cos theta C) sec^2 theta + tan^2 theta D) cot^2 theta sin^2 theta/cos^2theta Answer: D
*April 19, 2008 by Lucy*

**trigonometry**

Can you draw the The solution for this: Establishing identities 1.) Sin²∅ (1+cot²∅) = 1 2.) (tan²B+1) cos²B = 1 3.) tan x ---------- = sin x sec x 4.) 1 1 ------- + ------- = 2csc²∅ 1+cos∅ 1-cos Please help me, i cant understand it.
*January 20, 2015 by alyn*

**Trig**

Please help with this one. I've worked it out in so many ways and can't tell what's correct. sinA sinA ----- - ------ 1+sinA 1-sinA Which answer is correct for the problem above? a) 1+cotA b) sinA tanA c) -2tan^2A d) secA cscA common denominator: 1-sin^2 A and that is equal to...
*December 9, 2006 by Jasmine*

**Precalculus check answers help!**

1.) Find an expression equivalent to sec theta sin theta cot theta csc theta. tan theta csc theta sec theta ~ sin theta 2.) Find an expression equivalent to cos theta/sin theta . tan theta cot theta ~ sec theta csc theta 3.) Simplify (tan^2 theta + 1)/(tan^2 theta) . csc2 ...
*May 28, 2012 by Kelsey *

**Precalculus check answers help!**

1.) Find an expression equivalent to sec theta sin theta cot theta csc theta. tan theta csc theta sec theta ~ sin theta 2.) Find an expression equivalent to cos theta/sin theta . tan theta cot theta ~ sec theta csc theta 3.) Simplify (tan^2 theta + 1)/(tan^2 theta) . csc2 ...
*May 30, 2012 by Kelsey *

**Trigonometry**

Verify the identities. 1.) SIN[(π/2)-X]/COS[(π/2)-X]=COT X 2.) SEC(-X)/CSC(-X)= -TAN X 3.) (1 + SIN Y)[1 + SIN(-Y)]= COS²Y 4.) 1 + CSC(-θ)/COS(-θ) + COT(-θ)= SEC θ (Note: Just relax through verifying/solving these nice fun looking math problems! ...
*February 14, 2013 by AwesomeGuy*

**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 sin(ƒÎ/6) = cos(ƒÎ/3) = 1/2 ...
*August 24, 2011 by jenny*

**TRIG**

what is another form of: sin (A+B) sin (A-B)/ cos^2 A cos^2 B a) cos^2 A - cos^2 B b) tan^2 A - tan^2 B c) tan^2 A - tan^2 B d) sin^2 A - sin^2 B please show the steps you take to get to the answer! thank you
*November 26, 2010 by rossi*

**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 and 5pi/3 and then ...
*March 23, 2008 by Alex*

**trig**

find the exact solutions 2cos^2x+3sinx=0 the way it stands, that is a "nasty" question. Are you sure the second term isn't 2sin(2x) ? no, its as i wrote it. then it's got me stymied, I must be missing something rather obvious, sorry! thanks for trying! 2cos^2x+3sinx=0 2-2sin^...
*April 16, 2007 by Devon*

**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 = cos pi/3 = 1/2 cos...
*August 25, 2011 by jenny*

**trig**

I dont understand this. can you please tell how you got each answer? describe how the graph of each function is related to a basic trigonometric graph. 1. y= 1/2cos x 2. y= 2cos x+1 3. y= sin x-4 4. y= sin(x-4) 5. y= sin(3x) 6. y= cos(1/2x) 7. y= -cos x 8. y= -cos x+2 9. y= -...
*February 10, 2012 by BreAnne*

**Trigonometry**

Hello all, In our math class, we are practicing the trigonometric identities (i.e., sin^2(x)+cos^2(x)=1 or cot(x)=cos(x)/sin(x). Now, we are working on proofs that two sides of an equation are equal (for example, sin(x)*csc(x)=1; sin(x)csc(x)=sin(x)/sin(x)=1; 1=1). I am not ...
*February 25, 2008 by Timothy*

**math (trig)**

Find sin(x/2) if sin(x)= -0.4 and 3pi/2 < or equal to (x) < or equal to 2pi Let's use cos 2A = 1 - 2sin2 A and we can match cos x = 1 - 2sin2 (x/2) so we will need cos x we know sin x = -.4 and x is in the fourth quadrant, so the cosine will be positive. Drawing a right ...
*July 15, 2007 by aziiancaligirl*

**Trig**

Find the exact values of the six trigonometric functions 0 if the terminal side of 0 in standard position contains the points(-5,-4). (0 is not the number zero I don't know what its called) I have to find r first. r=sqrt x^2+y^2 r=sqrt -5^2+-4^2 r=sqrt 41 sin=y/r sin=-4/sqrt ...
*March 6, 2008 by Jon*

**Math - Solving for Trig Equations**

Solve the following equation for 0 less than and/or equal to "x" less than and/or equal to 360 -- cos^2x - 1 = sin^2x -- Attempt: cos^2x - 1 - sin^2x = 0 cos^2x - 1 - (1 - cos^2x) = 0 cos^2x - 1 - 1 + cos^2x = 0 2cos^2x - 2 = 0 (2cos^2x/2)= (-2/2) cos^2x = -1 cosx = square ...
*November 22, 2007 by Anonymous*

**Ap Calc AB**

Determine (dy/dx) using implicit differentiation. cos(X^2Y^2) = x I'm really confused what to do now..i think the next steps are: d/dx [cos(X^2*Y^2)] = d/dx [x] = -sin(X^2*Y^2)* ((X^2*2Y dy/dx) + (Y^2*2X)) = 1 = -2YX^2 sin(X^2*Y^2) dy/dx + -2XY^2sin(X^2*Y^2) = 1 = -2YX^2 sin(X...
*October 16, 2007 by Student*

**Pre-Calc**

How do I solve this? My work has led me to a dead end. tan(45-x) + cot(45-x) =4 my work: (tan45 - tanx)/(1+ tan45tanx) + (cot45 - cotx)/(1 + cot45cotx) = 4 (1-tanx)/(1+tanx) + (1-cotx)/(1+cotx) = 4 Then I found a common denominator, giving me this: (2-2cotxtanx)/(1+cotx+tanx+...
*February 7, 2007 by Jess*

**Math**

Which of these are NOT a trigonometric identity? A.) 1-cos^2x=sin^2x B.) sin^2x+1=cos^2x C.) 1+cot^2x=csc^2x D.) sec^2x-1=tan^2x
*February 7, 2015 by Alanie*

**trigo math**

7. Prove that tan B sin B + cos B = sec B. 11. Prove that tanλ cos^2λ +sin^2λ/sinλ = cos λ + sin λ. 12. Prove that 1+tanθ/1+tanθ = sec^2θ+2tanθ/ 1-tan^2θ. 21. Prove that sin^2w-cos^2w/ tan w sin w + cos w tan w = cos...
*December 13, 2012 by RUDY*

**Math-Trig**

1. Create an algebraic expression for sin(arccosx-arcsin3x) 2. The cosx=4/5, x lies in quadrant 4. Find sin x/2 3.Determine all solutions in (0,2pie) for sin4xsin^2x=3, cot^2v(3-1)cotx=v(3), cos^2x=cosx, and tan^2x-6tanx+4=0 4. Solve; sin(∏/2-x)=1/sec 5. Solve; cot+4x+...
*April 14, 2009 by Hujinson*

**Maths Calculus Derivatives**

Find the first derivative for the following functions 1) f(x) = sin(cos^2x) cos(sin^3x) 2) f(x) = ( tan 2x - tan x ) / ( 1 + tan x tan 2x ) 3) f(x) = sin { tan ( sqrt x^3 + 6 ) } 4) f(x) = {sec^2(100x) - tan^2(100x)} / x
*October 22, 2011 by Yousef*

**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<X<360. sin(x-360)sin(90-x)tan(-x)/cos(90+x) =0,5 2.A.prove that 8/sin^2A - 4/1...
*October 3, 2013 by katlego ratsoma*

**Trig.**

tan^2BeatacscBeta-tan^2 (simplify) (sin/cos)^2Beta times 1/sin-(sin/cos)^2 (sin^2/cos^2)-(sin^2/cos^2)=-sin/cos Is this correct?
*January 10, 2010 by Tara*

**Math **

cos(tan + cot) = csc only simplify one side to equal csc so far I got this far: [((cos)(sin))/(cos)] + [((cos)(cos))/(sin)] = csc I don't know what to do next
*March 18, 2011 by Amy*

**Trigonometry**

Prove that sin^2(Omega) - Cos^2(Omega) / tan(Omega) sin(Omega) + cos(Omega) tan(Omega) = cos(Omega) - cot (Omega) cos (omega) If could explain, please. That would be great (:
*August 3, 2012 by Marie*

**Math-Trigonometry**

Show that if x, y, and z are consecutive terms of an arithmetic sequence, and tan y is defined, then (sin x + sin y + sin z) / (cos x + cos y + cos z) = tan y. So I tried letting x = y-k (since x,y,z are consecutive terms of an arithmetic sequence), then z= y+k So we get (sin(...
*November 7, 2013 by Sam*

**Pre-Cal**

verify the identity sin x(1 - 2 cos^2 x + cos^4 x) = sin^5 x 1-2cos^2 x looks like 2cos^2x-1 its just backwards. I am not sure where to start.
*February 28, 2010 by Hannah*

**Pre-Calc**

How would you prove this identity? (sin^3(x)+cos^3(x))÷(1-2cos^2(x)) = (sec(x)-sin(x))÷(tan(x)-1)
*May 10, 2012 by Anna*

**Math**

There are no typos and no work b/c I don't know how to do them. Thanks. 1)Find cos theta if sin theta=3/5 and 90 degrees<theta<180 degrees. A)4/5 B)-4/5 C)square root of 34/5 D)-square root of 34/5 I chose A 2)Simplify:1-csc^2theta/cot^2theta A)-1 B)1 C)tan^2theta D)1/...
*February 14, 2008 by Jon*

**Pre-calc**

Verify this identity. How would you prove it (sin^3(x)+cos^3(x))÷(1-2cos^2(x)) = (sec(x)-sin(x))÷(tan(x)-1)
*May 10, 2012 by Beatrice*

**math trigono**

1. If tanθ = –√3 , what is the value of cot ? 2. Find the value of 3sec2.4. (Round to the nearest tenth.) 7. if θ is a standard position angle and cotθ = 1.85, in which quadrant(s) could θ lie? 14.if sinθ = -4/5 and tanθ = -4/3, what...
*December 12, 2012 by Stan*

**Pre Cal**

could someone please tell me what the other angle identity of tan is? Thank you much! "...other angle identity of tan x"? in relation to which "other" ? there are many identities dealing with the tangent. The most important is probably tan x = sin x/cos x The Pythagorean ...
*May 23, 2007 by Marie*

**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 pi)). with ...
*April 14, 2012 by Crystal*

**math**

how do I simplify these? 1. (Cot/1-tan) + (Tan/1-Cot) - Tan - Cot 2. (1+cos) (csc-cot)
*February 10, 2009 by kayla*

**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 degrees A.)(sq root 6...
*June 9, 2011 by HotMath*

**math**

Determine the values of sin, cos, tan, csc, sec and cot at (-3, -3) on the terminal arm of an angle in standard position 2. If cos θ = 2/3 and 270° < θ < 360° then determine the exact value of 1/cot
*January 19, 2011 by steph*

**Math**

Solve this equation algebraically: (1-sin x)/cos x = cos x/(1+sin x) --- I know the answer is an identity, and when graphed, it looks like cot x. I just don't know how to get there. I tried multiplying each side by its conjugate, but I still feel stuck. This is what I have so ...
*October 18, 2009 by Momo*

**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 dont know. Thanks for the help
*May 25, 2010 by anonymous*

**trig**

Verify the equation is an identitiy: cot(x)tan(x+pi) - sin(pi-x)cos((pi/2)-x) = cos^2x Thanks
*April 27, 2011 by Chris*

**TRIG!**

Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6 x=1 - (3/4)sin^2 2x work on one side only! Responses Trig please help! - Reiny, Monday, February 23, 2009 at 4:27pm LS looks like the sum of cubes sin^6 x + cos^6 x = (sin^2x)^3 + (cos^2x)^3 = (sin^2x+cos...
*February 23, 2009 by hayden*

**Math, Pre-Calc**

the original problem was: Solve: sin(3x)-sin(x)=cos(2x) so far i've gooten to: sin(x)(2sin(x)cos(x)-1)=cos^2(x)-sin^2(x) Where would I go from here?
*April 23, 2009 by Katie*

**math**

use the quotient and reciprocal identities to simplify the given expression cot t sin t csc t sin t tan t cot t cot t sec t
*October 11, 2011 by Anonymous*

**Calc.**

Differentiate. y= (cos x)^x u= cos x du= -sin x dx ln y = ln(cos x)^x ln y = x ln(cos x) (dy/dx)/(y)= ln(cos x) (dy/dx)= y ln(cos x) = (cos x)^x * (ln cos x) (dx/du)= x(cos x)^(x-1) * (-sin x) = - x sin(x)cos^(x-1)(x) (dy/dx)-(dx/du)= [(cos^x(x))(ln(cos(x)))-(x sin(x)cos^(x-1...
*March 9, 2011 by Chelsea*

**calculus**

Differentiate. y= (cos x)^x u= cos x du= -sin x dx ln y = ln(cos x)^x ln y = x ln(cos x) (dy/dx)/(y)= ln(cos x) (dy/dx)= y ln(cos x) = (cos x)^x * (ln cos x) (dx/du)= x(cos x)^(x-1) * (-sin x) = - x sin(x)cos^(x-1)(x) (dy/dx)-(dx/du)= [(cos^x(x))(ln(cos(x)))-(x sin(x)cos^(x-1...
*March 10, 2011 by Chelsea*

**math**

if 0<A<90 and Sin A+ cos A+ tan A+cot A+sec A+cosec A =7 then prove that sin 2A is a root of (x)^2 -44x-36=0
*August 29, 2014 by soumitra*

**MATH**

Hi, I really need help with these questions. I did some of them halfway, but then I got stuck. Would you please help me? Thank you so much. Prove the identity.... 1. sec x + tan x(1-sin x/cos x)=1 1/cos x + sin x/cos x(cos^2 x/cos x)=1 1+sin x/cos x(cos^2x/cos x)=1 I got stuck...
*January 2, 2014 by LIZZIE010*

**Math**

the original problem was: Solve: sin(3x)-sin(x)=cos(2x) so far i've gotten to: sin(x)(2sin(x)cos(x)-1)=cos^2(x)-sin^2(x) Where would I go from here?
*April 23, 2009 by Katie*

**math**

how would you find the angle to (3)^.5sin(2x)-2cos(2x)+2sin^2(x)=1 I know that you have to use the trig identities but then when i substitue the sin and cos(2x) in i don't know what to do. please help
*May 3, 2009 by mike*