设区域D由圆x<sup>2</sup>+y<sup>2</sup>=2ax(a﹥0)围成,则二重积分∫∫<sub>D</sub>e<sup>-x<sup>2</sup>-y<sup>2</sup></sup>dσ=()

题目类型: 单选题

题目内容

设区域D由圆x2+y2=2ax(a﹥0)围成,则二重积分∫∫De-x2-y2dσ=()

题目选项

A. 2∫0π/2dθ∫02acosθe-r2dr
B. -(π/2)π/2dθ∫02acosθe-r2dr
C. 0πdθ∫02acosθe-r2rdr
D. -(π/2)π/2dθ∫02acosθe-r2rdr

正确答案

D

题目解析

令x=rcosθ,y=rsinθ,则: ∫∫De-x2-y2dσ=∫-(π/2)π/2dθ∫02acosθr•e-r2dr=∫-(π/2)π/2dθ∫02acosθe-r2rdr

题目纠错