Precalculus
posted by Melinda .
What two common identities are most useful for simplifying 2tanx/sin^2x + cos^2x  tan^2x?
Two identities are: sin^2x + cos^2x = 1 and tan2x=2tanx/1tan^2x

2tanx/(sin^2x) + cos^2x  tan^2x?
or
2tanx/(sin^2x + cos^2x)  tan^2x?
or
2tanx/(sin^2x + cos^2x  tan^2x? )
??????????