Antiderivative : A function $F$ is called antiderivative of a function $f$ if the derivative $F^{\prime}$ equals $f.$ The difference between two antiderivatives $F_1$ and $F_2$ of $f$ is a constant. According to the fundamental theorem of calculus we can calculate integrals of $f$ using an antiderivative $F$ of $f$ as $\int \limits_{a}^{b} f(x)dx=F(b)-F(a).$