Question

Question #5c90e

Answer 1

`int_0^pi sin^2(7x) dx = pi/2`

Explanation:

`int_0^pi sin^2(7x) dx = 1/2 int_0^pi (1-cos(14x))dx`

`int_0^pi sin^2(7x) dx = 1/2 int_0^pi dx - 1/2 int 1/14cos(14x)d(14x)`

`int_0^pi sin^2(7x) dx = [x/2 - 1/28 sin(14x)]_0^pi`

`int_0^pi sin^2(7x) dx = (pi/2 - 1/28 sin(14pi)) - (0/2 -1/28sin(0))`

`int_0^pi sin^2(7x) dx = pi/2`