Integrals Resulting in Inverse Trigonometric Functions

Failed to parse (syntax error): {\displaystyle \int\dfrac{du}{\sqrt{a^2−u^2}} & = \arcsin \left(\dfrac{u}{a}\right)+C \\ \int\dfrac{du}{a^2+u^2}&=\dfrac{1}{a}\arctan \left(\dfrac{u}{a}\right)+C \\ \int\dfrac{du}{u\sqrt{u^2−a^2}}&=\dfrac{1}{a}\text{arcsec} \left(\dfrac{|u|}{a}\right)+C }

Integration into Inverse trigonometric functions using Substitution by The Organic Chemistry Tutor

Integrating using Inverse Trigonometric Functions by patrickJMT