Please show how you solve these two problems for vector calculus. Please do these numbers: (7 PART A, B, C, D, E, F, G) AND (8 PART A AND B) :) refrences: Multivariable Calculus; 6th edition; McCallum, Hughes-Hallett, Gleason, et al.; Wiley.

7. Use the level curves of the function z = f (x, y) to decide the sign of the following partial derivatives. Q. 4 5 '1 '5 . q l I) a. HP) b. MP) c. MP) d. film) e. 1:31P) f. Sketch the direction of grad f at P and Q g, Where is grad f longer? At P or at Q? why? 8. The concentration of the salt ina uid at (x, y,z) is given by C(x,y,z) = x4 +y4 +x2z2mg lcm3.You are at the point (1 , -l, l). a. In which direction you have to move for the concentration to increase fastest. b. Suppose you move at a speed of 5 cm/sec. How fast is the concentration changing with respect to time when you move in the direction you found in part a