Please solve questions 5 and 6

5. Consider a function f (x, y) = 'fxzy 1. 3) Find the gradient of f. b) Using the gradient function found above, nd the rate of change of f at P = (1, 2) in the direction of the vector 17 = (3, 4). 6. Use Stokes' Theorem to compute H5 curl F - dS whereF = (y, z, 0) and surface S is such that its boundary has positive orientation and is given by the vector r(t) = (0, cos t , sin t), 0 S t S 2.7:. (Note: cos 2t = l 25in2 t)