In previous sections, various formulas have been introduced
to calculate derivatives. However, it is not possible to have a formula
for every possible situation. Thus, basic formulas like d(xn)/dx
= nxn-1 need to be generalized so they can be used in a variety
Suppose y = (x2 + 1)3,
how can dy/dx be calculated using derivative formula?
Let f(u) = u3, where u = g(x) = x2 + 1. Then
The derivative of f and g can be calculated according to derivative
formula. A rule is needed to calculate the derivative of F which is a
composite function. This rule is named as Chain Rule.