In the method of variation of parameters we used indefinite integrals [in (49) and (78)]....

In the method of variation of parameters we used indefinite integrals [in (49) and (78)]. However, we could use definite

integrals in those formulas, instead, if we choose. Specifically, show that, in place of (49),

is also correct, for any choice of the constantsα1,α2(although normally one would chooseα1 andα2to be the same).