Integration of the form


Differentiating g(x) with respect to t, we have
g'(x) dx = dt
F(t) + C
F(g(x)) + C
Note 1:

Note 2:

Example:

Suggested answer:





Integration using trigonometric identities
When the integrand consists of trigonometric function, we use suitable trigonometric identities to simplify the function so that it can be integrated. Few identities are given below for ready reference.(1) 
(3) 
(5) 
(7) 

Example:
Integrate the function sinx. sin2x sin3x.
Suggested answer:




