8.15 problem 21

Internal problem ID [637]

Book: Elementary differential equations and boundary value problems, 10th ed., Boyce and DiPrima
Section: Chapter 3, Second order linear equations, 3.3 Complex Roots of the Characteristic Equation , page 164
Problem number: 21.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _missing_x]]

\[ \boxed {y^{\prime \prime }+y^{\prime }+\frac {5 y}{4}=0} \] With initial conditions \begin {align*} [y \left (0\right ) = 3, y^{\prime }\left (0\right ) = 1] \end {align*}

Solution by Maple

Time used: 0.016 (sec). Leaf size: 19

dsolve([diff(y(x),x$2)+ diff(y(x),x)+125/100*y(x) = 0,y(0) = 3, D(y)(0) = 1],y(x), singsol=all)
 

\[ y \left (x \right ) = \frac {{\mathrm e}^{-\frac {x}{2}} \left (5 \sin \left (x \right )+6 \cos \left (x \right )\right )}{2} \]

Solution by Mathematica

Time used: 0.016 (sec). Leaf size: 25

DSolve[{y''[x]+y'[x]+125/100*y[x]==0,{y[0]==3,y'[0]==1}},y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to \frac {1}{2} e^{-x/2} (5 \sin (x)+6 \cos (x)) \]