Function easingDerivative

easingDerivative(
    type: number,
    x: number,
    easingLeft?: number,
    easingRight?: number,
): number
Derivative of an RPE easing at x.
Parameters
- type: number
  Easing type (1–28).
- x: number
  Progress ∈ [0, 1].
- easingLeft: number = 0
  Left sub-range boundary.
- easingRight: number = 1
  Right sub-range boundary.
Returns number
- Defined in easing.ts:228