Question 5 (0.5 points] Please note the two parts in this question are not related. (a) Find an equation of the tangent plane to the surface of z = 2w2y + leggy'92) at (1,3,7). (b) Given that the function T = f(a:, y, z) is a differentiable function with f(2,1,3) = 1, f$(2,1,3) = 2, fy(2,1,3) = 3, fz(2,1,3) = 4, find the linear approximation and the differential of the function at (-2,1,-3). Use the differential to estimate the total change AT when x is increased by 0.04, y is decreased by 0.05, and z is increased by 0.03. Enter your answer in the blank below. Round your answer to two decimal places. Your