Hi, here's a really tough thinking question that has me totally stumped. Could someone please show me how to approach it?

Determine a sine function, F, and a cosine function, G, such that y= (squareroot of 2)sin(pi(x-2.25)) can be written in the form of F-G.

The solution at the back is:

f(x): sin(pi(x))

g(x): cos(pi(x))

I have no idea where to start...