Question

Integral x cos 2x dx ialah

Answer 1

1/2 x sin 2x + 1/4 cos 2x

Answer 2

Misalkan u=x maka du=dx
              dv=cos 2x dx maka v=1/2 * sin2x
integral (x cos 2x ) dx = x * 1/2 * sin 2x - integral 1/2 * sin 2x dx
                                = x/2 * sin 2x + 1/4 * cos 2x + C