Question

Help me prove this identity my math friends!

Answer 1

\[\frac{ 1 + \cos x}{ 1-\cos^2 x } = \frac{ 1 }{ 1-\cos x }\]

Answer 2

hint use difference of two squares rule for the denominator :
\[a^2 - b^2 = (a-b) (a+b)\]

Answer 3

so you want to focus on \[1-\cos^2x \]
note:\[\cos^2x = cosx \times cosx\]

Answer 4

ooooh, why couldn't I have thought of the difference of two squares! It's not so obvious when looking at cosines hehe. Thanks @butterflydreamer for your help.

Answer 5

yeah xD I was stumped for a bit too :) happy to help!