方程式の解を確かめる
SimplifyまたはFullSimplifyを使って解がその方程式を満足することを証明する.
Solve[x ^ 2 + x + 1 == 0, x]x ^ 2 + x + 1 == 0 /. %//SimplifyDSolve[y''[x] + y[x] == Exp[x], y, x]y''[x] + y[x] == Exp[x] /. First[%]//Simplifysoln = DSolve[y''[x] - Exp[x]y[x] == 0, y, x]y''[x] - Exp[x]y[x] == 0 /. First[soln]//Simplifyy''[x] - Exp[x]y[x] == 0 /. First[soln]//FullSimplify