9.2.21 problem problem 38

Internal problem ID [955]
Book : Differential equations and linear algebra, 4th ed., Edwards and Penney
Section : Section 5.3, Higher-Order Linear Differential Equations. Homogeneous Equations with Constant Coefficients. Page 300
Problem number : problem 38
Date solved : Wednesday, February 05, 2025 at 04:51:18 AM
CAS classification : [[_3rd_order, _missing_x]]

\begin{align*} y^{\prime \prime \prime }-5 y^{\prime \prime }+100 y^{\prime }-500 y&=0 \end{align*}

With initial conditions

\begin{align*} y \left (0\right )&=0\\ y^{\prime }\left (0\right )&=10\\ y^{\prime \prime }\left (0\right )&=250 \end{align*}

Solution by Maple

Time used: 0.009 (sec). Leaf size: 17

dsolve([diff(y(x),x$3)-5*diff(y(x),x$2)+100*diff(y(x),x)-500*y(x)=0,y(0) = 0, D(y)(0) = 10, (D@@2)(y)(0) = 250],y(x), singsol=all)
 
\[ y = 2 \,{\mathrm e}^{5 x}-2 \cos \left (10 x \right ) \]

Solution by Mathematica

Time used: 0.004 (sec). Leaf size: 19

DSolve[{D[y[x],{x,3}]-5*D[y[x],{x,2}]+100*D[y[x],x]-500*y[x]==0,{y[0]==0,Derivative[1][y][0] ==10,Derivative[2][y][0] ==250}},y[x],x,IncludeSingularSolutions -> True]
 
\[ y(x)\to 2 \left (e^{5 x}-\cos (10 x)\right ) \]