1. ## (cos^2x-sin^2x)/cos^2x+sinxcosx=1-tanx

Can someone PLEASEEEEEE help me prove this trig identity.

I did it down to where I have
LS:
sinx/cosx

RS:
-sinx

I am not sure where I went wrong,

2. LHS:
For numerator use formula

a^2 - b^2 = (a-b)(a+b)

So

cos^2(x) - sin^2 (x) = (cos(x) - sin(x)) (cos(x) + sin(x))

Denominator

cos^2(x) +cos(x)sin(x) = cos(x) (cos(x) +sin(x))

Divide numerator by denominator

The things in bold get cancelled

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One more thing try to avoid writing like thissssssss

3. Until you show your steps, I'm afraid we can't be sure where you went wrong, either. Sorry!

Please reply with a clear listing of your work and reasoning so far. Thank you!

4. Sorry to disappoint you SHOULD start a new thread for a new problem

Take Care of Yourself & Rules

5. Originally Posted by ADARSH
LHS:
For numerator use formula

a^2 - b^2 = (a-b)(a+b)

So

cos^2(x) - sin^2 (x) = (cos(x) - sin(x)) (cos(x) + sin(x))

Denominator

cos^2(x) +cos(x)sin(x) = cos(x) (cos(x) +sin(x))

Divide numerator by denominator

The things in bold get cancelled

-------------------------------------

One more thing try to avoid writing like thissssssss