A root checker

You will write a function for the left side of a quadratic equation, use it to test roots, and pick the roots out of a list.

The idea. A number is a root of $ax^2 + bx + c = 0$ when the left side is $0$ there. A computer works with decimals, so test whether the value is very close to $0$.

Your tasks.

1. In value, return $ax^2 + bx + c$ for the given $x$.
2. In is_root, return True when the value is closer to $0$ than 0.000000001.
3. Set roots to the numbers of candidates that are roots of $2x^2 - 5x - 3 = 0$, in the same order.