Calcolare (x(1-y)) dxdy
dove
D = {(x, y) R2 | 0 < y < 1/2, y x < 1-y2}.
Soluzione
Si ha
D x(1-y)dxdy = 01/2(y1-y2x(1-y)dx)dy =
= 01/2(1-y)(y1-y2 xdx)dy = 01/2(1-y)(x2/2)|y1-y2dy =
01/2(1-y)((1-2y2)/2)dy = (y/2 - y3/3 - y2/4 + y4/4)|01/2 =
= (48 - 16 - 12 2 + 6 2)/(96 2) = 2/6 - 1/16.