How to show d/dx(tanx)^3=3 (tanx)^4+3(secx)^2-3?

1 Answer
Feb 26, 2018

Please refer to a Proof in the Explanation.

Explanation:

By the Chain Rule,

ddx(tanx)3=3(tanx)2ddx(tanx),

=3(tanx)2(sec2x),

=3(tanx)2{(tanx)2+1},

=3(tanx)4+3(tanx)2,

=3(tanx)4+3{(secx)21},

=3(tanx)4+3(tanx)23, as desired!