大学高数题……求大神解答,越详细越好

2025-04-26 15:58:22
推荐回答(1个)
回答1:

原式=∫∫(Dxy) (1-x^2-y^2)dxdy
=∫(0,2π)dθ∫(0,1)(1-r^2)rdr
=2π*[(r^2)/2-(r^4)/4)]|(0,1)
=π/2