Consider z as a function of the variables x, y which is defined by z = In(x*y3 ) + y and let P(-1, -1) be a point. Also consider the vectors u = (0, B), w = (-a, B), such that lull = 130. If 121\\130 Duz(P) = 130 And Duz(P) = - 103 V 130 130 determine: the value of a: the value of B