Problem 9. True or False? Please motivate your answer.

(a) There is a function f such that fr = r + 4y and f, = 3x - y. (b) If f(x, y) - las (r, y) - (a, b) along the r-axis and along the y-axis, then lim f(x, y) = e. (z,y) -(a,b) Problem 10. Let z be a function defined implicitly by 2 = 1. 22 Find at the point