Letx+c=tdx=dtatx=a−c,t=x+c=aatx=b−c,t=x+c=bI=∫baf(t)dt=∫baf(x+c)dx
If ∫f(x)dx=F(x), then ∫5×f(x)dx=F(x)5, because integration is the inverse process of differentiation