# Question:phase diagram

## Question:phase diagram

Maple
```Hi
How to get from the differential equation:diff(x(t), t, t)+c*(diff(x(t), t))+k*sin(x(t)) = 0;print(`output redirected...`);
/ d  / d      \\     / d      \                                |--- |--- x(t)|| + c |--- x(t)| + k sin(x(t)) = 0              \ dt \ dt     //     \ dt     /
which transforms a differential equation of the phase trajectories
DEtools[convertsys](diff(diff(x(t), t), t)+c*(diff(x(t), t))+k*sin(x(t)) = 0, [], [x(t)], t, x, y);
[                                             [                     d      ]  [[y[1] = x[2], y[2] = -c x[2] - k sin(x[1])], [x[1] = x(t), x[2] = --- x(t)], [                                             [                     dt     ]  ```
```               ]  undefined, []]               ]subs([[y[1] = x[2], y[2] = -c*x[2]-k*sin(x[1])], [x[1] = x(t), x[2] = diff(x(t), t)], undefined, []][1], [Diff(x[1], t) = y[1], Diff(x[2], t) = y[2]]);
[ d                d                              ]             [--- x[1] = x[2], --- x[2] = -c x[2] - k sin(x[1])]             [ dt               dt                             ]
and with specific points (0, 0), (± PI, 0), (± 2Pi, 0) get to show the following phase diagram```

HerClau

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