Let\(I= \int \sqrt{x^2+3x} \: dx\)
=\(\int \sqrt{x^2+3x+\frac{9}{4}-\frac{9}{4}}dx\)
=\(\int \sqrt{\bigg(x+\frac{3}{2}\bigg)^2-\bigg(\frac{3}{2}\bigg)^2}dx\)
It is known that,\(\int \sqrt{x^2-a^2}dx=\frac{x}{2}\sqrt{x^2-a^2}-\frac{a^2}{2}\log\mid x+\sqrt{x^2-a^2\mid}+C\)
∴\(I= \frac{\bigg(x+\frac{3}{2}\bigg)}{2}\sqrt{x^2+3x}-\frac{\frac{9}{4}}{2}\log \mid \bigg(x+\frac{3}{2}\bigg)+\sqrt{x^2+3x}\mid+C\)
=\(\frac{(2x+3)}{4}\sqrt{x^2+3x}-\frac{9}{8}\log \mid \bigg(x+\frac{3}{2}\bigg)+\sqrt{x^2+3x}\mid+C\)
Let \( f : (0, \infty) \to \mathbb{R} \) be a twice differentiable function. If for some \( a \neq 0 \), } \[ \int_0^a f(x) \, dx = f(a), \quad f(1) = 1, \quad f(16) = \frac{1}{8}, \quad \text{then } 16 - f^{-1}\left( \frac{1}{16} \right) \text{ is equal to:}\]

There are many important integration formulas which are applied to integrate many other standard integrals. In this article, we will take a look at the integrals of these particular functions and see how they are used in several other standard integrals.
These are tabulated below along with the meaning of each part.
