Real Area Hyperbolic Sine of x over a in Logarithm Form

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Theorem

\(\ds \arsinh \dfrac x a\) \(=\) \(\ds \map \ln {\frac {x + \sqrt {x^2 + a^2} } a}\)
\(\ds \) \(=\) \(\ds \map \ln {x + \sqrt {x^2 + a^2} } - \ln a\)


Proof

\(\ds \arsinh \frac x a\) \(=\) \(\ds \map \ln {\frac x a + \sqrt {\paren {\frac x a}^2 + 1} }\) Definition of Real Area Hyperbolic Sine
\(\ds \) \(=\) \(\ds \map \ln {\frac x a + \sqrt {\frac {x^2 + a^2} {a^2} } }\)
\(\ds \) \(=\) \(\ds \map \ln {\frac x a + \frac {\sqrt {x^2 + a^2} } a}\)
\(\ds \) \(=\) \(\ds \map \ln {\frac {x + \sqrt {x^2 + a^2} } a}\)
\(\ds \) \(=\) \(\ds \map \ln {x + \sqrt {x^2 + a^2} } - \ln a\) Difference of Logarithms

$\blacksquare$


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