**Note:- if y = cos(x) ; then dy/dx = -sinx**

Now,

` `

`f(theta) = {(theta)+1}cos(theta)`

thus, `f'(theta) = cos(theta) - {(theta) + 1}sin(theta)`

``

` `

**Note:- if y = cos(x) ; then dy/dx = -sinx**

Now,

` `

`f(theta) = {(theta)+1}cos(theta)`

thus, `f'(theta) = cos(theta) - {(theta) + 1}sin(theta)`

``

` `