prod-sum

Getting a sum and a product.

• Math.sum(numbers, mapper?)
• Math.prod(numbers, mapper?)

Math.sum([1,2,3,4])
// 10

Math.prod([1,2,3,4])
// 24

// sum of squares

Math.sum([1,2,3,4], x => x**2)
// 1^2 + 2^2 + 3^2 + 4^2
// 30

function hypot(...args) {
  return Math.sqrt(
    Math.sum(args, x => x**2)
  );
}

hypot(1,2,3,4)
// 5.47722558

Math.hypot(1,2,3,4)
// 5.47722558