Differential calculus, a branch of calculus, is the study of finding out the rate of change of a variable compared to another variable, by using functions. It is a way to find out how a shape changes from one point to the next, without needing to divide the shape into an infinite number of pieces. Differential calculus is the opposite of integral calculus. It was developed in the 1670s and 1680s by Sir Isaac Newton and Gottfried Leibniz.