Function sincos_rrule 

pub fn sincos_rrule<S: ScalarAd>(x: S, cotangents: (S, S)) -> S

Reverse rule for sincos.

Examples

use chainrules::sincos_rrule;

let dx = sincos_rrule(0.25_f64, (1.0, 1.0));
assert!((dx - (0.25_f64.cos() - 0.25_f64.sin())).abs() < 1e-12);