Q.5) (a) Find and sketch the domain of the function f(x, y) = cos (y - x2 - 1). (b) Find fx, fox and fy if f(x, y) = sin(xy + coshy). (c) Use implicit differentiation to find or and ou oz if cosh(xyz) = 22 + e-z2 (d) Using the chain rule, determine w in terms of t if w = x/z ty/z, x = cost, y = sin't and z = 1/t