证明u=1⼀√(x^2+y^2+z^2)满足方程Ȣ^2u⼀Ȣx2+Ȣ^2u⼀Ȣy^2+Ȣ^2u⼀Ȣz^2=0

2024-12-19 16:37:40
推荐回答(1个)
回答1: