12.13 problem 19.3 (a)

Internal problem ID [13309]

Book: Ordinary Differential Equations. An introduction to the fundamentals. Kenneth B. Howell. second edition. CRC Press. FL, USA. 2020
Section: Chapter 19. Arbitrary Homogeneous linear equations with constant coefficients. Additional exercises page 369
Problem number: 19.3 (a).
ODE order: 3.
ODE degree: 1.

CAS Maple gives this as type [[_3rd_order, _missing_x]]

\[ \boxed {y^{\prime \prime \prime }+4 y^{\prime }=0} \] With initial conditions \begin {align*} [y \left (0\right ) = 4, y^{\prime }\left (0\right ) = 6, y^{\prime \prime }\left (0\right ) = 8] \end {align*}

Solution by Maple

Time used: 0.016 (sec). Leaf size: 18

dsolve([diff(y(x),x$3)+4*diff(y(x),x)=0,y(0) = 4, D(y)(0) = 6, (D@@2)(y)(0) = 8],y(x), singsol=all)
 

\[ y = 6+3 \sin \left (2 x \right )-2 \cos \left (2 x \right ) \]

Solution by Mathematica

Time used: 0.021 (sec). Leaf size: 19

DSolve[{y'''[x]+4*y'[x]==0,{y[0]==4,y'[0]==6,y''[0]==8}},y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to 3 \sin (2 x)-2 \cos (2 x)+6 \]