tan^2x - sin^2x = sin^2x*tan^2x
The Attempt at a Solution
This is how my teacher solved it.
______ - ______
sin^2x - cos^2x*sin^2x
= sin^2x (1-cos^2x)
thus giving the answer. I dont understand what happends on the third line. How can 1-cos^2x be bracketed if cos^2x*sin^2x are one term, even though they equal one, how can that equal 1-cos^2x?