Question

关于二重积分的,

Answer 1

1. C∫(0,+∞)∫(0,+∞)e^[-(2x+y)] dxdy

=C∫(0,+∞) -(1/2)e^[-(2x+y)]|[x=(0,+∞)] dy

=C∫(0,+∞) -(1/2) [e^(-∞)-e^(-y)] dy

=C∫(0,+∞) (1/2)e^(-y) dy

=-(C/2)e^(-y)|(0,+∞)

=-(C/2)[e^(-∞)-e^0]