6.16 problem 66

Internal problem ID [5930]

Book: DIFFERENTIAL EQUATIONS with Boundary Value Problems. DENNIS G. ZILL, WARREN S. WRIGHT, MICHAEL R. CULLEN. Brooks/Cole. Boston, MA. 2013. 8th edition.
Section: CHAPTER 7 THE LAPLACE TRANSFORM. 7.3.1 TRANSLATION ON THE s-AXIS. Page 297
Problem number: 66.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _linear, _nonhomogeneous]]

Solve \begin {gather*} \boxed {y^{\prime \prime }+4 y-\left (\left \{\begin {array}{cc} 1 & 0\le t <1 \\ 0 & 1\le t \end {array}\right .\right )=0} \end {gather*} With initial conditions \begin {align*} [y \relax (0) = 0, y^{\prime }\relax (0) = -1] \end {align*}

Solution by Maple

Time used: 0.445 (sec). Leaf size: 45

dsolve([diff(y(t),t$2)+4*y(t)=piecewise(0<=t and t<1,1,t>=1,0),y(0) = 0, D(y)(0) = -1],y(t), singsol=all)
 

\[ y \relax (t ) = -\frac {\sin \left (2 t \right )}{2}+\frac {\left (\left \{\begin {array}{cc} 0 & t <0 \\ 1-\cos \left (2 t \right ) & t <1 \\ \cos \left (2 t -2\right )-\cos \left (2 t \right ) & 1\le t \end {array}\right .\right )}{4} \]

Solution by Mathematica

Time used: 0.009 (sec). Leaf size: 65

DSolve[{y''[t]+4*y[t]==Piecewise[{{1,0<=t<1},{0,t>=1}}],{y[0]==0,y'[0]==-1}},y[t],t,IncludeSingularSolutions -> True]
 

\begin{align*} y(t)\to {cc} \{ & {cc} -\cos (t) \sin (t) & t\leq 0 \\ \frac {1}{4} (-\cos (2 t)-2 \sin (2 t)+1) & 0<t\leq 1 \\ \frac {1}{4} (\cos (2-2 t)-\cos (2 t)-2 \sin (2 t)) & \text {True} \\ \\ \\ \\ \\ \end{align*}