\(∫\)\(\frac {1}{9x^2+6x+5} dx\) = \(∫\frac {1}{(3x+1)^2+(2)^2}dx\)
\(Let \ (3x+1) = t\)
\(∴ 3dx = dt\)
⇒ \(∫\frac {1}{(3x+1)^2+(2)^2}dx\) \(=\) \(\frac 13 ∫\frac {1}{t^2+2^2} dt\)
\(=\frac 13 [\frac 12\ tan^{-1}(\frac t2)]+C\)
\(=\frac 16\ tan^{-1}(\frac {3x+1}{2})+C\)
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.