69.33.12 problem 841

Internal problem ID [18581]
Book : A book of problems in ordinary differential equations. M.L. KRASNOV, A.L. KISELYOV, G.I. MARKARENKO. MIR, MOSCOW. 1983
Section : Chapter 3. Section 24.2. Solving the Cauchy problem for linear differential equation with constant coefficients. Exercises page 249
Problem number : 841
Date solved : Thursday, October 02, 2025 at 03:15:05 PM
CAS classification : [[_2nd_order, _with_linear_symmetries]]

\begin{align*} x^{\prime \prime }+x&=t \end{align*}

Using Laplace method With initial conditions

\begin{align*} x \left (0\right )&=0 \\ x^{\prime }\left (0\right )&=1 \\ \end{align*}

✓ Maple. Time used: 0.093 (sec). Leaf size: 5

ode:=diff(diff(x(t),t),t)+x(t) = t; 
ic:=[x(0) = 0, D(x)(0) = 1]; 
dsolve([ode,op(ic)],x(t),method='laplace');
 

\[ x = t \]

✓ Mathematica. Time used: 0.009 (sec). Leaf size: 6

ode=D[x[t],{t,2}]+x[t]==t; 
ic={x[0]==0,Derivative[1][x][0 ]==1}; 
DSolve[{ode,ic},x[t],t,IncludeSingularSolutions->True]
 

\begin{align*} x(t)&\to t \end{align*}

✓ Sympy. Time used: 0.034 (sec). Leaf size: 3

from sympy import * 
t = symbols("t") 
x = Function("x") 
ode = Eq(-t + x(t) + Derivative(x(t), (t, 2)),0) 
ics = {x(0): 0, Subs(Derivative(x(t), t), t, 0): 1} 
dsolve(ode,func=x(t),ics=ics)
 

\[ x{\left (t \right )} = t \]