Write the Word or Phrase That Best Completes Each Statement $f ( x ) = - 3 x ^ { 6 } - 4 x ^ { 5 } - 5 x ^ { 4 } + 2 x ^ { 2 } + 6$

Short Answer

Write the word or phrase that best completes each statement or answers the question.
Provide the missing information.
-What is the maximum number of turning points of the graph of $f ( x ) = - 3 x ^ { 6 } - 4 x ^ { 5 } - 5 x ^ { 4 } + 2 x ^ { 2 } + 6$