**TI82** TxtView file generated by CalcText - Kouriˇ Laplace}˙Laplace d^2s ------ = s"(t) dt^2 e(t) = U(t-1) - U(t-2) t € ]-oo;1[ : 0 t € [1;2[ : 1 - 0 t € [2;+oo[ : 1 - 1˙Õ