(2) Consider the function f : R4 - R given by f (x, y, Z, W) = (1 + z - xyw + e2w-z, (1 + y) sin(w2 - 2x)). (a) Find the quadratic approximation Jof of f at the point P = (0, 0, 0, 0), and use this approximation to obtain an estimate for f(0.1, 0.1, -0.1, -0.1). (b) Now consider the function g : R2 - R' given by g(x, y) = (xery, tan(2 + y - x), y cos(xy)). We can compose the maps f and g to obtain a smooth function go f : R* - R. Use the chain rule to compute Dp(g . f), where P = (0, 0, 0, 0)