In this tutorial we shall discuss the integral of the secant cubed of , and this integration can be evaluated by using integration by parts. But first we break the power of the function from cube into square and one power of the function. Then we can use integration by parts of that function because we know the formula for the integration of secant square of from previous tutorials.
The integral of the secant cubed of is of the form
First we break into and , and now the integral (i) becomes
and are the first and second functions that form integration by parts. Using the formula for integration by parts, we have
Using the formula above, equation (ii) becomes
Now using trigonometric identity , we have
From our original problem , using this value we have