Finding the 1st derivative of the function in a) we use the quotient rule, since the function is a rational expression. The function in b) is a composite function. There is an inner function (cos x) and there is an outer function (the exponent 4)so we can either use the mental method or the chain rule. The last one is an implicite function. Here we differentiate each term of the expression with respect to x and then make dy/dx the subject. ‪@EndzeMathsSolutions-mp1wn‬