2.3.34 Gradient and Directional Derivative

Condition: for this function \ (z (x, y) \) Find: a) \ (d z \) b) \ (\ left. \ Operatorname {grad} z \ right | _ {m} \), c) \ (| \ Operatorname {Grad} z | _ {M} \ MID \). \ [z = e^{x} \ cdot \ cos y, \ quad m (1; 0) \]