For each of problems 1-5, find the differentials of f and g at the relevant points, and use these to determine the differential of the composite h = f(g(x) ) at the given point To.f(x, y) = (x2 - y2, zey) while g(a, b) = (7ab, In(a + b)), at the point (ao, bo) = (2, -1). f(x, y, z) = xy - 22, while g(r, s, t) = (s, -r, r2 + $2 + t2), at the point (ro, so, to) = (1, 1, 0)