code: function() {
              var new_array = [0], l = this.coeffs.length;
              for(var i=0; i<l; i++) {
                  var c = new Frac(i+1);
                  new_array[c] = this.coeffs[i].divide(c);
              }
              this.coeffs = new_array;
              return this;
          }
docs: Integrates the polynomial
  @returns {Polynomial}