To solve the integral \(\int 5x \sqrt{5x^2 - 5} \, dx\), we can use a substitution method. Let's set \(u = 5x^2 - 5\), which simplifies the expression under the square root. Then, compute \(du\) in terms of \(dx\) and substitute back into the integral to solve it in terms of \(u\).
Step 1: Identify the Integral and Use Substitution
To solve the integral \(\int 5x \sqrt{5x^2 - 5} \, dx\), we start by using a substitution method. Let \(u = 5x^2 - 5\). Then, the derivative \(du\) with respect to \(x\) is \(du = 10x \, dx\), or \(dx = \frac{du}{10x}\).
Step 2: Substitute and Simplify
Substitute \(u\) and \(dx\) into the integral:
\[
\int 5x \sqrt{u} \cdot \frac{du}{10x} = \frac{1}{2} \int \sqrt{u} \, du
\]
Step 3: Integrate with Respect to \(u\)
The integral \(\frac{1}{2} \int \sqrt{u} \, du\) can be solved as:
\[
\frac{1}{2} \cdot \frac{2}{3} u^{3/2} = \frac{1}{3} u^{3/2}
\]
Step 4: Substitute Back in Terms of \(x\)
Substitute back \(u = 5x^2 - 5\) into the expression:
\[
\frac{1}{3} (5x^2 - 5)^{3/2}
\]
Step 5: Simplify the Expression
Simplify the expression to match the output:
\[
\frac{5\sqrt{5}}{3} x^2 \sqrt{x^2 - 1} - \frac{5\sqrt{5}}{3} \sqrt{x^2 - 1}
\]