myfun= Sin[x + y]

samm =Table[myfun/.y->i,{i,0,5,1}]

Length[samm]

Plot[samm,{x,0,20},PlotStyle-> {Red,Green,Blue,Yellow,Pink,Black}]

ode1 = D[x[t],{t,2}] == Sin[t]

DSolve[ode1,x[t],t]

ode1 = D[x[t],{t,2}] == x[t]Sin[t]

DSolve[ode1,x[t],t]

mysol =NDSolve[{ode1,x[0]==1,x'[0]==0},x[t],{t,0,10}]

Plot[x[t]/.mysol,{t,0,10}]