Why does a function return NaN in JS?

Question

JavaScript

there is a function:

function intDiv(x,y){
    return [(x-x%y)/y,x%y];
  };

So everything is fine
console.log(intDiv(2/2));
And so (NaN,NaN):

var a = 2;
var b = 2;
console.log(intDiv(a/b));

Answer 1

console.log(intDiv(a, b));