Sorry, i'm stuck, here goes....
In the first two parts of the question, you are asked to show that:
which i have done, and it's all fine and dandy
However, the last part confuzes me....
If , show that:
The problem is i'm not sure what actually means. I understand it to be: f is a function of two variables, x and y, and f is a function of two variables, u and v, and these two functions are equal. But u and v are themselves functions of x and y so what is f?
A push in the right direction would be greatly appreciated!