u=ln(根号(x^2+y^2+z^2))相关计算

2025-03-23 15:28:02
推荐回答(1个)
回答1:

div(gradu) = (э2/эx2 + э2/эy2 + э2/эz2)u
= 1/(x*x + y*y + z*z)