What is formula transformation in physics?

Question

What is formula transformation in physics?

Answer 1

A formula transformation may be used to change an equation in one set of coordinates (say) x, y, z into another coordinate system (say) r, θ, φ.

For example, the cartesian equation: -

div²ψ =  Ã¢ÂˆÂ‚²ψ + ∂²ψ + ∂²ψ

............____....____...____

...........∂x² .... ∂y² ... ∂z²

becomes, in spherical polar coordinates: -

div²ψ =  Ã¢ÂˆÂ‚²ψ +  2.∂ψ + ∂²ψ +  cotθ.∂ψ  + ... 1 ... ∂²ψ

............____.... _ ____...____ .. ___ __ ...... _____ ___

...........∂r² .... . r∂r ...  Ã¢ÂˆÂ‚θ² ......  r² ∂θ .... r².sin²θ ∂φ²