如图
(1)
∫(0->1) x(1-2x) dx
=∫(0->1) (x-2x^2) dx
= [ (1/2)x^2 - (2/3)x^3 ] |(0->1)
=1/2 -2/3
=-1/6
(2)
∫(0->1) 2x(1-x)^2 dx
=∫(0->1) (2x-4x^2+2x^3) dx
=[ x^2 - (4/3)x^3 + (1/2)x^4 ]|(0->1)
=1 - 4/3 + 1/2
= 1/6
原式 = ∫<0, 1> (2x-4x^2)dx = [x^2-(4/3)x^3]<0, 1> = -1/3
原式 = ∫<0, 1> 2x(1-2x+x^2)dx = ∫<0, 1> (2x-4x^2+2x^3)dx
= [x^2-(4/3)x^3+(2/4)x^4]<0, 1> = 1/6