Question

If x=e^s cost and y=e^s sint and z=u(x,y)=v(s,t) show that:
(∂^2 z)/(∂s^2 )+ (∂^2 z)/(∂t^2 )=(x^2+ y^2 ) ( (∂^2 z)/(∂x^2 )+ (∂^2 z)/(∂y^2 ) )

Answer 1

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