Cosine - radians

Algorithm

/**
 * Cosine - radians: 
 *
 * @param x1 angle in radians
 * @return {Array}
 */
function neuron556(x1)
{
math.config({number: 'BigNumber', precision: 64}); return [math.eval('cos('+Number(x1)+')').toString()];
}

console.log(neuron556(862));