Trigonometric Identities


by Cabal
Tags: identities, trigonometric
Cabal
Cabal is offline
#1
Feb1-05, 07:15 PM
P: 1
I can, for the mort part, understand how to derive and "proof" most of my Identity work, but some of the more complex (in my feeble opinion) problems give me quite a bit of trouble.

Can anyone explain these?

"Use the fundamental identities to simplify to sines and cosines:
tan(^2)x - (csc(^2)x/cot(^2)x) "
Someone told me the answer was (-1) and I had no idea how to get that.

and

"Confirm the Identity:
(sinx)/(1-cosx) + (sinx)/(1+cosx) = 2cscx"

Any explanations would be greatly appreciated! Thanks!
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dextercioby
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#2
Feb1-05, 07:23 PM
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HINT:Use the definitions of "composite" functions (tan,cotan,sec,csc) and the fundamental identity
[tex]\sin^{2}x+\cos^{2}x=1 [/tex]

Daniel.
Hurkyl
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#3
Feb1-05, 07:37 PM
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My usual advice is to convert everything into sines and cosines, and clear all denominators.


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