∫∫√(y²-xy)dxdy=∫dy∫√(y²-xy)dx
=∫dy∫√(y²-xy)(-1/y)d(y²-xy)
=∫{(-1/y)(2/3)[(y²-xy)^(3/2)]│}dy
=∫[(-1/y)(2/3)(0-y³)]dy
=(2/3)∫y²dy
=(2/3)(y³/3)│
=(2/3)(1/3-0)
=2/9
∫∫√(y²-xy)dxdy=∫dy∫√(y²-xy)dx
=∫dy∫√(y²-xy)(-1/y)d(y²-xy)
=∫{(-1/y)(2/3)[(y²-xy)^(3/2)]│}dy
=∫[(-1/y)(2/3)(0-y³)]dy
=(2/3)∫y²dy
=(2/3)(y³/3)│
=(2/3)(1/3-0)
=2/9