As given by the question
There are given that the function
![f(x)=x^4-x^3+3x+1](https://img.qammunity.org/2023/formulas/mathematics/college/ymmpqot4g2yt86529gz3n95oyu9j2f3nlq.png)
Now,
By the defination, a polynomial of n degree, has a maximum turning points of:
![n-1](https://img.qammunity.org/2023/formulas/mathematics/high-school/o46gatkgmzcosrlf6o8cs224vf6e905alo.png)
Therefore, if you have the polynomial given in the problem, which is a polynomial of degree 4, that means (n=4).
The maximum number of turns can be obtained as following:
![\begin{gathered} n-1=4-1 \\ =3 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/4vi0by9sv7pdnsdm3yp7ji7ty8tvdgqp8r.png)
Hence, the maximum number of turns in the graph is 3.