Rationalizing Substitution is a special type of U-Substitution, radicals in function often cause problems when integrating, use rationalizing substitution we can transform the problem to help us solve them.

For example, sometimes our function contain something like \(\sqrt{x}\), in order to eliminate the “square root”, we can make substitution \(x = z^2\)，\(dx = 2z dz\). Then you may can solve function’s integration easier.