Question

differentiate y=sec^4 x - 2tan^2 x.
A.4sec^2 x tan ^3 x
B.-4sec^2 x tan ^3 x
c. 4sec^3 x tan ^2 x
d.-4 sec^3 x tan^2 x

Answer 1

A.

Answer 2

dy/dx=(sec^2)^2-2tanx^2
(1+tan^2x)^2-2tan^2x bcoz sec^2x=1+tan^2x
using (a+b)^2
1+2tan^2x+tan^4x-2tan^2x
1+tan^4x
finally
4tan^3xsec^2x

Answer 3

sorry.........i did't get u