Note:- If y = tanx ; then dy/dx = sec^2(x)

If y = sec(x) ; then dy/dx = sec(x)*tan(x)

Now,

`f(theta) = 3tan(theta)`

`f'(theta) = 3sec^2(theta)`

`f''(theta) = 3*2sec(theta)*sec(theta)*tan(theta)`

`or, f''(theta) = 6sec^2(theta)*tan(theta)`

``

Note:- If y = tanx ; then dy/dx = sec^2(x)

If y = sec(x) ; then dy/dx = sec(x)*tan(x)

Now,

`f(theta) = 3tan(theta)`

`f'(theta) = 3sec^2(theta)`

`f''(theta) = 3*2sec(theta)*sec(theta)*tan(theta)`

`or, f''(theta) = 6sec^2(theta)*tan(theta)`

``