Steps to Reproduce

1. I was reading the source code of Flutter and found a little mistake in spring_simulation.dart.
2. It is in line 185. When calculating the critical damping solution, I got a different result.
3. My calculation steps are as follows: y = (c1 + c2 * t) * e ^(r * t) get: v = c2 * e^(r * t) + (c1 + c2 * t) * r * e ^ (r * t) .
4. When t = 0, get: y = c1, v = c2 + c1 * r, then c2 = v - c1 * r .
5. So I think this code should be: "final double c2 = velocity - (r * distance);" , but not "final double c2 = velocity / (r * distance );".
6. I calculated many times and tried to make sure every step of my calculation was right, always got this result.
7. Was this a mistake or am I wrong?
8. Thank you.

Expected results:

Actual results: