Is $ \frac {1}{\sqrt{a^2-b^2}} $ = $\cosh^{-1}(\frac{a}{b})$
is this true or false?
Is $ \frac {1}{\sqrt{a^2-b^2}} $ = $\cosh^{-1}(\frac{a}{b})$
is this true or false?
This can't be true in principle: $\cosh^{-1}(\frac ab) = \cosh^{-1}(\frac{2a}{2b})$, but $\frac1{\sqrt{a^2-b^2}} \ne \frac1{\sqrt{(2a)^2-(2b)^2}}$...