Integral batas atas 3, integral batas bawah 1 (x+2)(x-1)dx

Integral TaK tentu

₁³∫ (x +2)(x - 1) dx  =
= ₁³∫ (x² + x - 2) dx
= [1/3 x³  + 1/2 x² - 2x ]³₁
= 1/3 (27-1) + 1/2 (9-1) -2(3-1)
= 26/3 - 4 - 4
= (26 -12 -12)/3
= (26-24)/3
= 2/3