\[\begin{array}{l}
 T12. \to \int {\sinh xdx}  = \cosh x + C \\ 
 {\rm{Dokaz}}\,{\rm{(Proof):}} \\ 
 \int {\sinh xdx}  = \left| \begin{array}{l}
 \cosh x = t \\ 
 \sinh xdx = dt \\ 
 \end{array} \right| = \int {dt}  = t = \cosh x \\ 
 \end{array}\]