Ideas on how to easily solve this long derivation?

[Kaasen]

Mod note: Moved from a Homework section
1. Homework Statement
I want to solve:
∇²E, for E = exp(ikr)/r, where r = √x²+y²+z²

Thus I must solve:
d²E/dx²+d²E/dy²+d²E/dy²

The derivatives themselves are simple, but very time-consuming! Can you think of any tricks I can use to simplify the calculation?

 

[Samy_A]

Homework Statement

I want to solve:
∇²E, for E = exp(ikr)/r, where r = √x²+y²+z²

Thus I must solve:
d²E/dx²+d²E/dy²+d²E/dy²

The derivatives themselves are simple, but very time-consuming! Can you think of any tricks I can use to simplify the calculation?

Since your function only depends on r, you could try a coordinate system that treats r nicely.