1. ## prove that cos^2x+tan^2xcos^2x=1

can you explain all steps please because:
I did it and I got down to LS:
(1-sin^2x)/sin^2x
so the answer on the left side would be 0,
but I dont think that is right, where would my error be?

2. Originally Posted by skeske1234
can you explain all steps please because:
I did it and I got down to LS:
(1-sin^2x)/sin^2x
so the answer on the left side would be 0,
but I dont think that is right, where would my error be?
$\tan^2(x) = \frac{\sin^2(x)}{\cos^2(x)}$

Hence:

$\cos^2(x) \tan^2(x) = \cos^2(x)\frac{\sin^2(x)}{\cos^2(x)}= \sin^2(x)$