I have to find the general solution for the differential equation $y''(x) - m^2y(x) = 0$I tried to solve this one by deriving the auxiliary equation as $M^2-m^2=0$ which gives $M = \pm m$ hence the general solutions is $c_1e^{mx} + c_2e^{-mx}$ but in the paper it's given the answer should be in the form of summation of hyperbolic functions,which is $c_1 \sinh mx + c_2 \cosh mx$
I haven't done anything much on hyperbolic,could anybody help me in this regard?