Arccosecant of Reciprocal equals Arcsine

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Theorem

Everywhere that the function is defined:

$\map \arccsc {\dfrac 1 x} = \arcsin x$

where $\arcsin$ and $\arccsc$ denote arcsine and arccosecant respectively.


Proof

\(\ds \map \arccsc {\frac 1 x}\) \(=\) \(\ds y\)
\(\ds \leadstoandfrom \ \ \) \(\ds \frac 1 x\) \(=\) \(\ds \csc y\) Definition of Real Arccosecant
\(\ds \leadstoandfrom \ \ \) \(\ds x\) \(=\) \(\ds \sin y\) Cosecant is Reciprocal of Sine
\(\ds \leadstoandfrom \ \ \) \(\ds \arcsin x\) \(=\) \(\ds y\) Definition of Real Arcsine

$\blacksquare$