Hello =)

Suppose that f(x,y) is a function of two variables with

fx (0,2) = 2 and fy (0,2) = -1

Using the chain rule, compute the numeral value of f theta ( r cos theta, r sin theta)

at r = 2, theta = pi/2

I know that if you sub the values of r and theta into f (with respect to theta, given above), you get the point (0,2).

I don't know how to make the connection, and therefore get the answer!

thanks in advance =)