1. Consider the function f(x,y)=(x-1)^2+3(y-2)^2+5

(a) Sketch a graph of this function to make a graph. Using your graph, what would you guess is the equation of the tangent plane at the point where x =1and y=2? Why?

(b) Use derivatives to compute the equation of the tangent plane described in part (a) and compare to your guess in (a).