Fundamental Identities

Trigonometric ratios and functions, the unit circle, inverse trig functions, identities, trig graphs, etc.
lorst789
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Fundamental Identities

Postby lorst789 » Mon Jul 29, 2013 2:52 pm

can everyone help solving my problem i cant understand please any one...

COTx + TANx = 2COSx CSCx - SECx CSCx

i need answer ASAP please

nona.m.nona
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Re: Fundamental Identities

Postby nona.m.nona » Tue Jul 30, 2013 1:41 am

lorst789 wrote:i cant understand....

COTx + TANx = 2COSx CSCx - SECx CSCx

What were the instructions? Are you supposed to solve via the use of fundamental trig identities, or is this an identity itself and you are needing to prove it? Which part are you not understanding?

lorst789
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Re: Fundamental Identities

Postby lorst789 » Wed Jul 31, 2013 6:05 am

i need to prove it.. sorry i forgot to put it :D

nona.m.nona
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Re: Fundamental Identities

Postby nona.m.nona » Wed Jul 31, 2013 12:30 pm

lorst789 wrote:Prove:

COTx + TANx = 2COSx CSCx - SECx CSCx

This site offers a lesson on proving trigonometric identities; you may access that lesson here.

The lesson recommends starting with the "messier" side of the equation which, in this case, would be the right-hand side (RHS). Another recommendation is to convert each trigonometric function to its equivalent in sine and cosine. This would create the following:

RHS = 2cos(x)csc(x) - sec(x)csc(x)
RHS = 2cos(x)[1/sin(x)] - [1/cos(x)][1/sin(x)]

Then combine and apply identities, as possible:

RHS = 2[cos(x)/sin(x)] - 1/[cos(x)sin(x)]
RHS = 2cos^2(x)/[cos(x)sin(x)] - 1/[cos(x)sin(x)]
RHS = [2cos^2(x) - 1]/[cos(x)sin(x)]

And so forth. If you are unable to complete this exercise, kindly please reply showing your steps, starting from what has been displayed for you above. Thank you.

lorst789
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Joined: Mon Jul 29, 2013 2:48 pm
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Re: Fundamental Identities

Postby lorst789 » Thu Aug 01, 2013 5:34 am

Thanks to your answer


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