added alternate solution to multiply using Exponentiation operator

calculator/calculator.js

@@ -20,6 +20,11 @@ const power = function(a, b) {
   return Math.pow(a, b);
 };
 
+//alternate solution using Exponentiation opertator
+const power = function(a, b) {
+  return a ** b;
+};
+
 const factorial = function(n) {
   if (n === 0) return 1;
   let product = 1;