I have the following rotation matrix:
[u = [cos θ -sin θ| [x
v] = |sin θ cos θ] y]
the rotation matrix is 2x2 (I apologize for my bad html skills)
And I need to show that the following is true:
d^2f/dx^2 + d^2f/dy^2 = d^2f/du^2 + d^2f/dv^2 (d=delta, so it's second derivative)
Any guidance will be greatly appreciated,
Cheers Tom