3. Let mappings F= (F1, F2) R² → R² and G = (G1, G2): R² → R² be defined by F₁(x1, x2) = x² + x2, G₁(y1, y2)=sin(y2), F2(x1, x2, x3) = x1 + x2, G2(y1, y2) = cos(y1). (i) Find the composition mapping GoF: R2 → R². (ii) By using the chain rule, find the derivative of the mapping Go F, that is [5 Marks] D(GF)(x1, x2). [15 Marks] (iii) Give reasons why the mapping GoF is differentiable at every x = R². [5 Marks]