How to take the integral of tangent

The video tutorial explains how to solve an integration problem involving the tangent of X by using the quotient identity to rewrite it as sine over cosine. The instructor then applies the substitution method, setting u equal to cosine of X, and proceeds to integrate the expression. The tutorial concludes with the integration result and a constant of integration.

Explain the process of negating the expression in the context of the problem.

What does the final expression of the integration represent?