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(2) Consider the function f : R4 - R' given by f ( x, y, Z, W) = (1+ x - zy - wyz, exz-w, 2y sin(w + x2)). (a) Find the quadratic approximation Jof of f at the point P = (0, 0, 0, 0). (b) Now consider the function g : RS - R given by g(x, y, z) = (sin(x - y), y cos(x2 - z2 - 1)). We can compose the maps f and g to obtain a smooth function g . f : R* - R. Use the chain rule to compute Dp(g . f), where P = (0, 0, 0, 0)