Primitive of Reciprocal of Root of 1 minus x squared/Arcsine Form

Corollary to Primitive of $\frac 1 {\sqrt {a^2 - x^2} }$: Arcsine Form

 * $\ds \int \frac 1 {\sqrt {1 - x^2} } \rd x = \arcsin x + C$

where $C$ is an arbitrary constant.

Proof
From Primitive of $\dfrac 1 {\sqrt {a^2 - x^2} }$: Arcsine Form:
 * $\ds \int \frac 1 {\sqrt {a^2 - x^2} } \rd x = \arcsin \frac x a + C$

The result follows by setting $a = 1$.