If you could answer these i would appreciate that thank you!

1. Let f(x, y, =) = 3x y' + 2yz. (10 points) (a) Compute the gradient of f at (1, -1,2). (b) Find the derivative of f at (1, -1, 2) in the direction of 7 = (2, -2, 1). (c) What is the greatest rate of change of f at (1, -1, 2)? 2. Let f(x, y) = Vc - ry. (10 points) y (a) Find an equation for the plane tangent to the graph of f at (1, -2). (b) Use differentials or your answer to part (a) to approximate f (0.98, -2.1). 3. Find the local minima/maxima, and saddle points of the given function. (12 p.) f(x,y) = xy + 2y' -2xy + 6 4. Find the global maximum and global minimum of f(x, y) = xy subject to the constraint 4x- + y'