9.54 problem 1909

Internal problem ID [9488]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 8, system of first order odes
Problem number: 1909.
ODE order: 1.
ODE degree: 1.

Solve \begin {align*} x^{\prime }\relax (t )&=a x \relax (t )+g y \relax (t )+\beta z \relax (t )\\ y^{\prime }\relax (t )&=g x \relax (t )+b y \relax (t )+\alpha z \relax (t )\\ z^{\prime }\relax (t )&=\beta x \relax (t )+\alpha y \relax (t )+c z \relax (t ) \end {align*}

Solution by Maple

Time used: 28.031 (sec). Leaf size: 54175

dsolve({diff(x(t),t)=a*x(t)+g*y(t)+beta*z(t),diff(y(t),t)=g*x(t)+b*y(t)+alpha*z(t),diff(z(t),t)=beta*x(t)+alpha*y(t)+c*z(t)},{x(t), y(t), z(t)}, singsol=all)
 

\[ \text {Expression too large to display} \] \[ \text {Expression too large to display} \] \[ \text {Expression too large to display} \]

Solution by Mathematica

Time used: 0.022 (sec). Leaf size: 1639

DSolve[{x'[t]==a*x[t]+g*y[t]+\[Beta]*z[t],y'[t]==g*x[t]+b*y[t]+\[Alpha]*z[t],z'[t]==\[Beta]*x[t]+\[Alpha]*y[t]+c*z[t]},{x[t],y[t],z[t]},t,IncludeSingularSolutions -> True]
 

\begin{align*} x(t)\to -c_3 \text {RootSum}\left [-\text {$\#$1}^3+\text {$\#$1}^2 a+\text {$\#$1}^2 b+\text {$\#$1}^2 c+\text {$\#$1} \alpha ^2-\text {$\#$1} a b-\text {$\#$1} a c+\text {$\#$1} \beta ^2-\text {$\#$1} b c+\text {$\#$1} g^2-a \alpha ^2+a b c-b \beta ^2-c g^2+2 \alpha \beta g\&,\frac {-b \beta e^{\text {$\#$1} t}+\alpha g e^{\text {$\#$1} t}+\text {$\#$1} \beta e^{\text {$\#$1} t}}{-3 \text {$\#$1}^2+2 \text {$\#$1} a+2 \text {$\#$1} b+2 \text {$\#$1} c+\alpha ^2-a b-a c+\beta ^2-b c+g^2}\&\right ]+c_2 \text {RootSum}\left [-\text {$\#$1}^3+\text {$\#$1}^2 a+\text {$\#$1}^2 b+\text {$\#$1}^2 c+\text {$\#$1} \alpha ^2-\text {$\#$1} a b-\text {$\#$1} a c+\text {$\#$1} \beta ^2-\text {$\#$1} b c+\text {$\#$1} g^2-a \alpha ^2+a b c-b \beta ^2-c g^2+2 \alpha \beta g\&,\frac {-c g e^{\text {$\#$1} t}+\text {$\#$1} g e^{\text {$\#$1} t}+\alpha \beta e^{\text {$\#$1} t}}{3 \text {$\#$1}^2-2 \text {$\#$1} a-2 \text {$\#$1} b-2 \text {$\#$1} c-\alpha ^2+a b+a c-\beta ^2+b c-g^2}\&\right ]+c_1 \text {RootSum}\left [-\text {$\#$1}^3+\text {$\#$1}^2 a+\text {$\#$1}^2 b+\text {$\#$1}^2 c+\text {$\#$1} \alpha ^2-\text {$\#$1} a b-\text {$\#$1} a c+\text {$\#$1} \beta ^2-\text {$\#$1} b c+\text {$\#$1} g^2-a \alpha ^2+a b c-b \beta ^2-c g^2+2 \alpha \beta g\&,\frac {\text {$\#$1}^2 e^{\text {$\#$1} t}+b c e^{\text {$\#$1} t}-\text {$\#$1} b e^{\text {$\#$1} t}-\text {$\#$1} c e^{\text {$\#$1} t}+\alpha ^2 \left (-e^{\text {$\#$1} t}\right )}{3 \text {$\#$1}^2-2 \text {$\#$1} a-2 \text {$\#$1} b-2 \text {$\#$1} c-\alpha ^2+a b+a c-\beta ^2+b c-g^2}\&\right ] \\ y(t)\to c_1 \text {RootSum}\left [-\text {$\#$1}^3+\text {$\#$1}^2 a+\text {$\#$1}^2 b+\text {$\#$1}^2 c+\text {$\#$1} \alpha ^2-\text {$\#$1} a b-\text {$\#$1} a c+\text {$\#$1} \beta ^2-\text {$\#$1} b c+\text {$\#$1} g^2-a \alpha ^2+a b c-b \beta ^2-c g^2+2 \alpha \beta g\&,\frac {-c g e^{\text {$\#$1} t}+\text {$\#$1} g e^{\text {$\#$1} t}+\alpha \beta e^{\text {$\#$1} t}}{3 \text {$\#$1}^2-2 \text {$\#$1} a-2 \text {$\#$1} b-2 \text {$\#$1} c-\alpha ^2+a b+a c-\beta ^2+b c-g^2}\&\right ]+c_3 \text {RootSum}\left [-\text {$\#$1}^3+\text {$\#$1}^2 a+\text {$\#$1}^2 b+\text {$\#$1}^2 c+\text {$\#$1} \alpha ^2-\text {$\#$1} a b-\text {$\#$1} a c+\text {$\#$1} \beta ^2-\text {$\#$1} b c+\text {$\#$1} g^2-a \alpha ^2+a b c-b \beta ^2-c g^2+2 \alpha \beta g\&,\frac {-a \alpha e^{\text {$\#$1} t}+\beta g e^{\text {$\#$1} t}+\text {$\#$1} \alpha e^{\text {$\#$1} t}}{3 \text {$\#$1}^2-2 \text {$\#$1} a-2 \text {$\#$1} b-2 \text {$\#$1} c-\alpha ^2+a b+a c-\beta ^2+b c-g^2}\&\right ]+c_2 \text {RootSum}\left [-\text {$\#$1}^3+\text {$\#$1}^2 a+\text {$\#$1}^2 b+\text {$\#$1}^2 c+\text {$\#$1} \alpha ^2-\text {$\#$1} a b-\text {$\#$1} a c+\text {$\#$1} \beta ^2-\text {$\#$1} b c+\text {$\#$1} g^2-a \alpha ^2+a b c-b \beta ^2-c g^2+2 \alpha \beta g\&,\frac {\text {$\#$1}^2 e^{\text {$\#$1} t}+a c e^{\text {$\#$1} t}-\text {$\#$1} a e^{\text {$\#$1} t}-\text {$\#$1} c e^{\text {$\#$1} t}+\beta ^2 \left (-e^{\text {$\#$1} t}\right )}{3 \text {$\#$1}^2-2 \text {$\#$1} a-2 \text {$\#$1} b-2 \text {$\#$1} c-\alpha ^2+a b+a c-\beta ^2+b c-g^2}\&\right ] \\ z(t)\to -c_1 \text {RootSum}\left [-\text {$\#$1}^3+\text {$\#$1}^2 a+\text {$\#$1}^2 b+\text {$\#$1}^2 c+\text {$\#$1} \alpha ^2-\text {$\#$1} a b-\text {$\#$1} a c+\text {$\#$1} \beta ^2-\text {$\#$1} b c+\text {$\#$1} g^2-a \alpha ^2+a b c-b \beta ^2-c g^2+2 \alpha \beta g\&,\frac {-b \beta e^{\text {$\#$1} t}+\alpha g e^{\text {$\#$1} t}+\text {$\#$1} \beta e^{\text {$\#$1} t}}{-3 \text {$\#$1}^2+2 \text {$\#$1} a+2 \text {$\#$1} b+2 \text {$\#$1} c+\alpha ^2-a b-a c+\beta ^2-b c+g^2}\&\right ]+c_2 \text {RootSum}\left [-\text {$\#$1}^3+\text {$\#$1}^2 a+\text {$\#$1}^2 b+\text {$\#$1}^2 c+\text {$\#$1} \alpha ^2-\text {$\#$1} a b-\text {$\#$1} a c+\text {$\#$1} \beta ^2-\text {$\#$1} b c+\text {$\#$1} g^2-a \alpha ^2+a b c-b \beta ^2-c g^2+2 \alpha \beta g\&,\frac {-a \alpha e^{\text {$\#$1} t}+\beta g e^{\text {$\#$1} t}+\text {$\#$1} \alpha e^{\text {$\#$1} t}}{3 \text {$\#$1}^2-2 \text {$\#$1} a-2 \text {$\#$1} b-2 \text {$\#$1} c-\alpha ^2+a b+a c-\beta ^2+b c-g^2}\&\right ]+c_3 \text {RootSum}\left [-\text {$\#$1}^3+\text {$\#$1}^2 a+\text {$\#$1}^2 b+\text {$\#$1}^2 c+\text {$\#$1} \alpha ^2-\text {$\#$1} a b-\text {$\#$1} a c+\text {$\#$1} \beta ^2-\text {$\#$1} b c+\text {$\#$1} g^2-a \alpha ^2+a b c-b \beta ^2-c g^2+2 \alpha \beta g\&,\frac {\text {$\#$1}^2 e^{\text {$\#$1} t}+a b e^{\text {$\#$1} t}-\text {$\#$1} a e^{\text {$\#$1} t}-\text {$\#$1} b e^{\text {$\#$1} t}+g^2 \left (-e^{\text {$\#$1} t}\right )}{3 \text {$\#$1}^2-2 \text {$\#$1} a-2 \text {$\#$1} b-2 \text {$\#$1} c-\alpha ^2+a b+a c-\beta ^2+b c-g^2}\&\right ] \\ \end{align*}