Question

If y = cos³ (sec² 2t), find `dy/dt`

Answer 1

y = cos³ (sec² 2t)

Applying chair Rule.

`dy/dt = 3 cos^2 (sec^2 2t) xx [(-sin (sec^2 2t)]xx2sec 2txxsec2t  x tan  2t xx2`

= − 12 cos² (sec² 2t) × (sec² 2t) × sin(sec² 2t) × tan2t