11.1   ODE No. 1913

$$\boxed{{\displaystyle \{\frac{\mathrm{d}}{\mathrm{d}t}x\left(t\right)=-x\left(t\right)(x\left(t\right)+y\left(t\right)),\frac{\mathrm{d}}{\mathrm{d}t}y\left(t\right)=y\left(t\right)(x\left(t\right)+y\left(t\right))\}}}$$

1. Problem in Latex
2. Mathematica input
3. Maple input

Mathematica: cpu = 0.032004 (sec), leaf count = 64 $$\left\{\{y(t)\to -\sqrt{c_1}\cot (\sqrt{c_1}t-\sqrt{c_1}{c}_2),x(t)\to -\sqrt{c_1}\tan (\sqrt{c_1}t-\sqrt{c_1}{c}_2)\}\right\}$$

Maple: cpu = 0.109 (sec), leaf count = 54 $$\{[\{x\left(t\right)=0\},\{y\left(t\right)={(\mathit{\_}\mathit{C}\mathit{1}-t)}^{-1}\}],[\{x\left(t\right)=\frac{1}{\mathit{\_}\mathit{C}\mathit{1}}\tanh \left(\frac{\mathit{\_}\mathit{C}\mathit{2}+t}{\mathit{\_}\mathit{C}\mathit{1}}\right)\},\{y\left(t\right)=-\frac{{\left(x\left(t\right)\right)}^2+\frac{\mathrm{d}}{\mathrm{d}t}x\left(t\right)}{x\left(t\right)}\}]\}$$