def f(c, a):
    b = jnp.sin((c * jnp.sum(jnp.cos((d * a)))))
    c = (0.9 * jnp.cos((d * jnp.sum(jnp.sin((c * a))))))
    return (c, b)
def f(c, a):
    b = jnp.sin((c * jnp.sum(jnp.cos((d * a)))))
    c = (0.9 * jnp.cos((d * jnp.sum(jnp.sin((c * a))))))
    return (c, b)