1) 8 turning points means 8 vertices, which implies minimum degree 9 (when the polynomial is x^2 the degree is 2 and it has one turning point).
2) 5 turning points means minimum degree 6, 3 zeros means minimum degree 3, the multiplication implies minimum degree 6+3 = 9
3) 5 times crossing the x - axis is 5 zeros, then the minimum degree is 5.
4) f(x)=x^14 + x^6 + x^9 + x^3,maximum number of turning points 14 -1 = 3 (remember one less than the grade is the maximum posible number of turning points, but it could be less, for example f(x) = x^2 has one turning point).
