Friday

April 18, 2014

April 18, 2014

Number of results: 7,500

**Trig**

What specific topics do you need help with? Trig identities are simply equivalent expressions...you should know the identities, and know how to substitute them into equations...everything else pretty much follows from that.
*Wednesday, January 6, 2010 at 6:54pm by Marth*

**trig**

Mmmhh, 5 consecutive trig questions without any work on your part, or any indication where you are having problems. Looks like homework dumping to me. Hint: A very effective way to prove identities is to change everything you see into sines and cosines using basic identities. ...
*Monday, November 12, 2012 at 7:35am by Reiny*

**Calculus 1**

i am having problems with the trig identities that and how to solve with sin squared. i have the formula. that hasn't helped me with the identities.
*Monday, October 15, 2012 at 11:32am by Chelle*

**small correction - Trig Identities**

My first line should have been: There is NO one correct and foolproof way to prove identities.
*Sunday, February 17, 2013 at 10:06am by Reiny*

**trig**

what you want to do is to show that using standard identities and algebraic manipulation, the left side can be made equal to the right side. cosx(tanx+cotx) change to sin,cos using trig identities cosx(sinx/cosx + cosx/sinx) now do some algebra cosx*sinx/cosx + cosx*cosx/sinx ...
*Sunday, November 25, 2012 at 2:34pm by Steve*

**Trig**

How do you express sin4x as a trigonometric funcition of x using the identities? I think that you are supposed to start with the sine sum identity and then use the double angle identities for sin2A and cos2A, but after that I get stuck...
*Wednesday, February 17, 2010 at 4:46pm by Taylor*

**Precalculus**

How would you solve this trig function: cos2x=sin^2-2 how do you know what trig identities to use?
*Saturday, August 6, 2011 at 5:39pm by Jess*

**trig**

TRIG Identities, Gr. 12: Prove: cot4x=1-tan^2x/2tan2x
*Thursday, May 23, 2013 at 2:56pm by Josh*

**trig! please help!**

to bobpursely: i need to simplify the expression using trig identities. and no i meant for there to only be x
*Sunday, May 13, 2012 at 8:59pm by Brianna*

**trig**

Let Q be an acute angle such that sinQ=.6. Find the values of the following using Trig Identities: cosQ and tanQ
*Tuesday, July 27, 2010 at 10:06pm by student*

**Trig**

Use Trig identities to verify that sec^4(x)-tan^4(x)=1+2tan^2(x), Only work with one side of the equation
*Tuesday, March 1, 2011 at 5:23pm by Anonymus*

**Trig Identities**

Please help...I'm not understanding trig identities and how to manipulate and express these two problems in their associated functions. Thanks a)Express as a function of cos (theta) 2 sin^2(theta) - 1 b)Express as a function of sin (theta) or cos (theta) tan^2(theta) - 2 sec(...
*Tuesday, January 6, 2009 at 6:46am by Donovan*

**trig**

Solving Trig Functions: How Do You Solve For Sin 7.5 Using Half-Angle and Double-Angle Identities?
*Wednesday, September 22, 2010 at 10:23pm by Spy[c]*

**trig**

2sin(4x)[(cos(3/2)x)(cos(5x/2)-sin((15/4)x)]+x can someone simplify this using trig identities?
*Sunday, May 13, 2012 at 9:08pm by Brianna*

**Trig**

Im having serious issues with verifying Trig. identities. Please help! Here is an example: (tanX-secX)^2= 1-sinX/1+sinX
*Monday, November 7, 2011 at 7:24pm by Rachel*

**Trigonometry - Identities and proof**

Show that cot((x+y)/2) = - (sin x - sin y)/(cos x - cos y) for all values of x and y for which both sides are defined. I tried manipulating both sides in terms of trig identities but I don't really have a solution....help would be appreciated, thanks.
*Wednesday, November 13, 2013 at 11:23am by Sam*

**Trig**

Are any of these three problems identities? 1. Cos^2x-sin^2x=1-2sin^2x 2. Sinxsecx=cosxcscx 3. Sec^4x-tan^4/sec^2x=1+sin^2x If so, how can you conclude that any of them are identities?
*Sunday, January 3, 2010 at 4:07pm by Melody*

**Trig**

Are any of these three problems identities? 1. Cos^2x-sin^2x=1-2sin^2x 2. Sinxsecx=cosxcscx 3. Sec^4x-tan^4/sec^2x=1+sin^2x If so, how can you conclude that any of them are identities?
*Sunday, January 3, 2010 at 6:01pm by Melody*

**trig**

use trig identities to rewrite: (1/(1-cos4v))-(1/(1+cos4v))
*Friday, August 26, 2011 at 12:31am by liz*

**trig**

testing if x = 20º LS = cot60/csc20 = sin20/tan60 = .1975 RS = cos20(1/sin40 - 1) = .5222 Your equation is NOT an identity. A check should always be your first step when proving complicated-looking trig "identities".
*Wednesday, October 21, 2009 at 10:08pm by Reiny*

**#3 of 6**

We have this: (3) Simplify: -5(cot^2theta-csc^2theta) A)5 B)-5 C)-5csc^2 theta D)5csc^2 theta I chose A You said B, right? Let's see if that's true. I will use x in place of theta to avoid having to write the word theta through and through. So, x = theta. cot^2 (x) = cos^2 (x...
*Thursday, February 14, 2008 at 3:28pm by Guido*

**math trig identities**

Anyone help!!!!!
*Thursday, January 20, 2011 at 11:03am by Sabrina*

**trig identities**

is that the answer?
*Tuesday, April 26, 2011 at 9:22pm by caitlyn*

**Trigonometry**

Use the trig Identities to find the other 5 trig functions. Problem 7.)Tan(90-x)=-3/8 8.)Csc x=-13/5 9.)Cot x=square root of 3 10.)Sin(90-x)=-.4563 11.)Sec(-x)=4 12.)Cos x=-.2351 I need HELP!
*Tuesday, January 5, 2010 at 4:09pm by Jennifer*

**trig identities**

yes, check it out with a calculator.
*Tuesday, April 26, 2011 at 9:22pm by Reiny*

**trig**

identities are equations. I don't see an equation.
*Monday, May 30, 2011 at 8:33pm by Reiny*

**trig**

We have trig identities. cscx - sinx to cotx(cos x). cscx is the reciprocal of the sine function. So, then: cscx = 1/sinx We now have: 1/sinx - sinx...Treat this like a fraction case. 1/sinx - sinx becomes (1 - sin^2x)/sinx Of course, (1 - sin^2x) is one of the Pythagorean ...
*Tuesday, February 19, 2008 at 11:24pm by Guido*

**trig**

I dont see any identities, no equal sign.
*Wednesday, April 16, 2008 at 10:52pm by bobpursley*

**Trig**

What is sin^2 - cos^2 x/ 1-2cos^2 x, using the identities.
*Sunday, May 4, 2008 at 10:52pm by Mary*

**Pre-Cal (verifying trig identities)**

what is rad?
*Thursday, February 12, 2009 at 10:04pm by bobpursley*

**Pre-Cal (verifying trig identities)**

radical
*Thursday, February 12, 2009 at 10:04pm by Crystal*

**Pre-Cal (verifying trig identities)**

Thanks, Reiny.
*Thursday, February 12, 2009 at 10:04pm by bobpursley*

**Math**

Actually it probably has something to do with trig identities...
*Tuesday, September 11, 2012 at 10:57pm by Mary*

**trig**

I will show you the first problem to give you an idea how to approach proving trig identities. Here are a few basic identities that will help: sinx/cosx = tanx secx = 1/cosx cos^2x + sin^2x = 1 Let's put everything into sine and cosine form and work the left hand side: (secx...
*Sunday, May 15, 2011 at 2:10pm by MathGuru*

**trig**

How do I prove these trig identities? secx-cosx/tanx =sinx And 1+sinx/cosx+ cox/ 1+sinx=2secx
*Sunday, May 15, 2011 at 2:10pm by Jill*

**Math (Trig)**

I don't think your equation is an identity, I tried several angles and the Left Side is not equal to the Right Side. Check your typing. In general, I try to prove these type of identities by changing everything to sines and cosines, unless I can recognize one of the common ...
*Wednesday, April 9, 2008 at 2:06pm by Reiny*

**trig pre calc**

cos x (sec x +cos x csc2x)=csc2x
*Sunday, May 13, 2012 at 8:16pm by trig identities*

**Trig**

verify following trigonometric identities. 1/sec0tan0 = csc0 = sin0
*Tuesday, August 24, 2010 at 8:30am by Jose*

**Trig Identities..**

Solve any way possibly? Thank you! 1-sin^2x/1-cosx
*Sunday, May 15, 2011 at 10:55pm by Jill*

**trig**

recall the basic identities: sin^2+cos^2 = 1 csc^2 = 1+tan^2
*Sunday, July 14, 2013 at 10:57am by Steve*

**Calculus**

oh and just to be clear you got this using trig identities right?
*Monday, December 13, 2010 at 9:36pm by dazed and confused*

**trig**

please help me. use trig. identities to find the exact value. tan 25° + tan 5° / 1- tan 25° tan 5°
*Friday, April 30, 2010 at 10:07pm by ann*

**trig**

please help me. use trig. identities to find the exact value. tan 25° + tan 5° / 1- tan 25° tan 5°
*Friday, April 30, 2010 at 10:14pm by ann*

**Trig**

tan(a-b) = [ tan a - tan b)/(1 + tan a tan b) You better learn those trig identities.
*Tuesday, December 27, 2011 at 6:42pm by Damon*

**identities trig?**

find all solutions to the equation in the interval [0,2pie] cos2x=cosx
*Tuesday, April 26, 2011 at 9:47pm by emily*

**Pre-calculus**

So, since you know Cos x= 0.8, plug in to the calculator Cos inv of 0.8. Do the same for Cos Y= 12/13. X=36.9 degrees Y=22.6 degrees I think that where you are in precalculus, you have to know these trig identities. You MUST memorize them as they are the basis of good ...
*Friday, February 17, 2012 at 12:58am by yoyoma*

**pre calculus 2**

use the fundamental trig. Identities to simplify tan^4x+2tan^2x+1
*Sunday, July 24, 2011 at 9:18pm by denise *

**Trig identities:(**

Sin4A - cos4A = sin2A - cos2A Can i just square root the left side??:O
*Saturday, February 23, 2013 at 7:43pm by Kristien*

**Trig**

Identities are trigonometric equations that must be valid for any value of the angle. That is only true for the first equation.
*Sunday, January 3, 2010 at 4:07pm by drwls*

**trig**

using the trigonometric identities find the exact (radical form) value of cos (105 degrees)
*Tuesday, April 13, 2010 at 8:10pm by spencer*

**trig. identities**

sin2x+sin2y=2sin(x+y)cos(x-y) Please helpp mee!! thank you sooo much really!!
*Tuesday, November 9, 2010 at 7:07pm by Sabrina*

**Trig!**

The identities cos(a-b)=cos(a)cos(b)sin(a)sin(b) and sin(a-b)=sin(a)cos(b)-cos(a)sin(b) are occasionally useful. Justify them. One method is to use rotation matricies. Another method is to use the established identities for cos(a+b) and sin (a+b).
*Tuesday, September 27, 2011 at 12:21pm by Elle*

**trig**

Evaluate giving exact values and identities. Calculator based solutions are not acceptable. Thanks for any help cos (4pi/3 3pi/4)
*Monday, June 2, 2008 at 9:17pm by Carmen*

**trig**

Evaluate giving exact values and identities. Calculator based solutions are not acceptable. Thanks for any help cos (7pi/12)
*Monday, June 2, 2008 at 9:18pm by Carmen*

**trig**

Evaluate giving exact values and identities. Calculator based solutions are not acceptable. Thanks for any help cos (-5pi/12)
*Monday, June 2, 2008 at 9:18pm by Carmen*

**trig**

Evaluate giving exact values and identities. Calculator based solutions are not acceptable. Thanks for any help sin (-pi/12)
*Monday, June 2, 2008 at 9:20pm by Bradley*

**Trig**

We started a new lesson on Monday on identities. Our test is tommorrow. I have no idea of what I'm doing! Can somebody help me study?
*Wednesday, January 6, 2010 at 6:54pm by Jennifer*

**Trig math**

how to split up using sum and difference identities cos (13pi/12) PLeaseeeeeeeeeee help!!! thanx a million
*Wednesday, November 17, 2010 at 12:56am by Sabrina*

**trig**

find all values of x on interval 0-2pi. (sin4x)(cos7x)=(cos4x)(sin7x) identities should be used.
*Monday, January 24, 2011 at 2:56pm by Ashten*

**Trig**

simplify the expression to a single term: (1-2Sin^2 X)^2 + 4sin^2 X Cos^2 X I'm not sure how to start this or which identities to use. Any suggestions?
*Monday, May 7, 2012 at 8:01pm by Anonymous*

**Mathematics - Trigonometric Identities**

I'm not suppose to use the inverse identities yet ...
*Thursday, November 8, 2007 at 6:17pm by Anonymous*

**Trigonometry**

They are called identities. One of the characteristics of identities is that they apply to all angles x. The above is not a correct identity, since correctly written, it would be: cos(x) = cos(-x) Other identities are sin²(x)+cos²(x)=1 sin(2A)=2sin(A)cos(A) ...
*Sunday, January 22, 2012 at 11:29pm by MathMate*

**Trigonometry**

Solve. 2sin(2Æ) + ã3 = 0 interval [0, 2Î) How do I start this? I feel like maybe Trig Identities, but I'm not really sure.
*Friday, September 16, 2011 at 12:26pm by Josh*

**Trigonometry**

Simplify the expression using trig identities: 1. (sin4x - cos4x)/(sin2x -cos2x) 2. (sinx(cotx)+cosx)/(2cotx)
*Sunday, July 15, 2012 at 6:29pm by Tasha*

**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!!
*Sunday, February 17, 2013 at 10:06am by Deepa*

**trig**

just drag out your good old trig identities: sin^2 a + cos^2 a = 1 You have a 3-4-5 and a 8-15-17 triangle. You could figure that out using the formula above. Next: sin(u+v) = sinu cosv + cosu sinv sin(u+v) = 3/5 * 8/17 + 4/5 * 15/17 and I guess you can take it from there . . .
*Sunday, December 18, 2011 at 11:20pm by Steve*

**math**

Prove the following identities: a) (cosec θ + cotθ)(cosecθ - cotθ) = cotθtanθ b) 2/(1 + sinθ) + 1/(1- sinθ) = (3sec^2)θ - tanθcosecθ I basically just have to prove Left HandSide = Right Hand Side
*Friday, July 18, 2008 at 12:04pm by Proving Identities Question (Trig.)*

**trigonometry**

recall that most fundamental of all trig identities sin^2 + cos^2 = 1 burn that into your brain in letters of fire. It is indispensable!
*Sunday, December 16, 2012 at 5:06pm by Steve*

**Trig Identities..lehlaka c.c**

2sinxcosx/1-cos =sinxcosx/1-cos=-sinx
*Sunday, May 15, 2011 at 10:55pm by thato*

**trig**

How to get 5degree without using calculator using identities?
*Friday, January 20, 2012 at 10:20pm by Laurnece*

**math**

how do i solve this using trig identities? 2 csc^2x = 3 cot^2x-1
*Tuesday, October 16, 2007 at 11:10pm by Kayla*

**trig**

what is the correct answer in trigonometric identities. DiViDE ; x^5 + 5x^4 - 2x^3 + 3x^2 + 2x + 1 by x + 3
*Thursday, February 2, 2012 at 7:15am by mien*

**math**

One of the basic trig identities says: cos 2A = cos^2 A - sin^2 A
*Monday, July 23, 2012 at 10:08am by Reiny*

**Trig**

Eight Fundamental Identities Sec thada - Cos thada How do I do this?
*Saturday, December 17, 2011 at 1:49pm by Don*

**math-trig**

Use the double angle identities to find sin2x if sinx= 1/square of 17 and cosx<0 . Give exact answer.
*Friday, September 24, 2010 at 12:28am by conner*

**trig**

Use trigonometric identities to find sec theta, given that tan theta = Radical 5/ 3.
*Friday, August 26, 2011 at 7:45pm by Davis*

**Calc**

y=uvw y'=vwu' + uvw'+uwv' It is just algebra, and probably some trig identities.
*Monday, October 15, 2012 at 11:20am by bobpursley*

**tRiG/ AlGeBrA**

1) Use double-angle identities to write the following expression, using trigonometric functions of x instead of 4x. cos 4x 2) Use half-angle identities to write the following expression, using trigonometric functions of x instead of x/4. sin x/4
*Monday, February 27, 2012 at 2:54am by CHEYANNE*

**Pre-Calculus/Trivia**

If x = sin(theta), these equations are identities, expressing other trig functions in terms of sin hey arise from the identity sin^2(theta) + cos^2(theta) = 1 As for real life and calculus, get familiar with the trig functions, and by the time you have mastered the techniques...
*Monday, February 20, 2012 at 9:22pm by Steve*

**Trig**

Column 1 Column 2 (sin theta + cos theta)sq 1 + 2sin theta cos theta Question : how do you get column 1 to be the same as column 2?? using the trig identities
*Saturday, December 17, 2011 at 4:35pm by Don*

**Pre-Cal (verifying trig identities)**

I think I have the same book as you Crystal... I have no clue how to solve this thing... :p
*Thursday, February 12, 2009 at 10:04pm by John*

**trig**

1) Use double-angle identities to write the following expression, using trigonometric functions of x instead of 4x. cos 4x 2) Use half-angle identities to write the following expression, using trigonometric functions of x instead of x/4. sin x/4
*Monday, May 28, 2012 at 11:36pm by marie*

**Pre-Cal (verifying trig identities)**

How would you verify the identity? sin^1/2x-cosx-sin^5/2xcosx=cos^3xradsinx
*Thursday, February 12, 2009 at 10:04pm by Crystal*

**trig**

I have to factor the expression and use fundamental identities: sins^2xcscx^2-sin^2x sec^4x-tan^4x
*Friday, October 7, 2011 at 9:32pm by Help pleaseee*

**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.
*Tuesday, March 25, 2014 at 6:40pm by Madison*

**trig**

use sum or difference identities to find the exact value of the trigonometric function: tan 345 please show work, i cant figure out what im doing wrong!
*Thursday, November 19, 2009 at 7:38pm by Anonymous*

**TRIG**

Verify the following identity. 1) sin(x+y) __________ = tanx+tany cosxcosy 2) Write cos3x in terms of cosx I cannot figure out how to solve for identities they are so hard. Any help appreciated!:)
*Sunday, October 23, 2011 at 5:34pm by ALISON*

**Trig**

Proving Identities: 2 columns (tan + cot)^2 = sec^2 + csc^2 I'm having trouble breaking down the left side to = the right side.. Any help please
*Sunday, January 8, 2012 at 7:38pm by Don*

**Trig Identities**

If tan(theta)=7/13 and cos(theta)<0, what is the exact value of sin(theta)?
*Monday, August 24, 2009 at 2:27pm by Anonymous*

**trig**

in proving trigonometric identities if cot theta sin theta = cos theta. what is the correct answer?
*Wednesday, February 1, 2012 at 7:18am by mien*

**trig**

what is the correct answer in proving trigonometric identities if tan theta/sin theta = sec theta
*Thursday, February 2, 2012 at 7:10am by mien*

**trig**

what is the correct answer in proving trigonometric identities if tan theta / sin theta = sec theta
*Thursday, February 2, 2012 at 7:12am by mien*

**trig**

use basic identities to simplify the expression. csc θ cot θ / sec θ
*Saturday, July 13, 2013 at 12:49pm by tony*

**Math - Trig - Double Angles**

Ugh...nevermind I'm so confused... If I did the right side, would it be more easy than the left side? I don't think I know how to expand with identities...
*Saturday, November 17, 2007 at 6:17pm by Anonymous*

**pre-calculus**

In google type : r=3cos2theta When you see list of results click on : Advanced Math: precal, trig identities, conversion You will see answer.
*Sunday, March 18, 2012 at 6:11pm by Bosnian*

**Math (trigonometry)**

Trigonometry identities are so hard... I need some help proving these identities: *Oh, and I'm only in grade 11, so the identities we use are quotient identity and Pythagorean identity. sinx/(sinx + cosx) = tanx/(1 + tanx) cos^2x - sin^2x = 2cos^2x - 1 Thanks! Lucy
*Sunday, April 13, 2008 at 9:53pm by Lucy*

**Calculus**

Use the Quotient Identities. (The "q" hints at that, too.) The Quotient Identities are the rules for tangent and cotangent.
*Saturday, November 24, 2007 at 1:32pm by Michael*

**Trigonometric Identities**

Which of the following are trigonometric identities, I have narrowed it down to two - (cscx + cotx)^2 = 1 OR sin^2(x)sec^2(x) + 1 = cot^2(x)csc^2(x)
*Thursday, March 24, 2011 at 5:33pm by Veronica*

**trig**

This must be in reference to a right-angled triangle in standard position with sides x, y, and r so that sinØ = y/r, cosØ = x/r and tanØ = y/x You should also know the three reciprocal identities. x^2 + y^2 = r^2 divide each term by y^2 x^2/y^2 + 1 = r^2/y^2 or cot^2 Ø + 1 = ...
*Thursday, September 1, 2011 at 10:27pm by Reiny*

**Algebra 2 to Reiny**

you are correct. You can test whether two trig expressions are equal by taking a non-standard angle, like 37°, and evaluating each expression If the question was to "simplify", I would consider the original expression simplified enough. Because of the many trig identities and ...
*Friday, June 11, 2010 at 12:03am by Reiny*

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