Question

if sinh x= 3/4 find cosh x?

Answer 1

Hmm so using your Square Identity,\[\Large\rm \cosh^2x-\sinh^2x=1 \qquad\to\qquad \sinh x=\sqrt{\cosh^2x-1}\]I think we can figure it out this way, yes?
Woops I meant to solve for cosh x >.< doh!

Answer 2

\[\Large\rm \cosh x=\sqrt{1+\sinh^2x}\]