Question

Which expression is equivalent to tan (-x)cos^2x?

A)-sin xcos x
B)sin xcos x
C) tan x + sin^2
D) tan x - sin^2
E) -tan x-sin^2x

Answer 1

Use the identity \(\sin^2 x + \cos^2 x = 1\).
Solve it for \(\cos^2 x\).
Then substitute it into the given expression.
What do you get?