The answer to your question is 30+4.+10+4
So than i understand it right and this 4 turning points mean 4 corners so from this result that this polynomial has minimum 360 degrees
hope this will help you
Algebra is Faster And Better Than “Basic” Math
Just as multiplying two by twelve is faster than counting to 24 or adding 2 twelve times, algebra helps us solve problems more quickly and easily than we could otherwise. Algebra also opens up whole new areas of life problems, such as graphing curves that cannot be solved with only foundational math skills.
Explanation

When taking derivatives of polynomials, we primarily make use of the power rule.
Power rule.

also, the derivate of a sum is the sum of the derivates
hence

Step 1
apply:

therefore, the answer is