answer : 5
For example
The quadratic equation has 1 tuning point. The degree of quadratic polynomial is 2
Cubic polynomial can have 2 turning points. The degree of cubic polynomial is 3
From this we conclude that if a polynomial has 'n' turning points, then the least possible degree is n+1
the graph of a polynomial has 4 turning points, so the least possible degree is
4+1 = 5
5 is the least possible degree of this polynomial
