\table[[8. Initial-Value Problems: In Problems below x,x((\pi )/(4))=\sqrt(2)x^(')((\pi )/(4))=2\sqrt(2)]]=\sqrt(2)x^(')((\pi )/(4))=2\sqrt(2)=c_(1)cost+c_(2)sint is a two-parameter family of solutions of the second-order DE x^('')+x=0. Find a solution of the second-order IVP consisting of this differential equation and the given initial conditions.