Question

Expression is not equivalent to (1 − sin2(x)) tan(-x).

Answer 1

Are You trying to find out the equivalent expression? or...

Answer 2

If you are looking for an expression that is no equivalent, then:

(cos^2(x) - 1) cot(-x)

Explanation:

The expression (cos^2(x) - 1) cot(-x) is not equivalent to (1 − sin2(x)) tan(-x).