At What Value of X Does the Function $f ( x ) = x ^ { 3 } - 3 x ^ { 2 } - 9 x$

question 173

Multiple Choice

At what value of x does the function $f ( x ) = x ^ { 3 } - 3 x ^ { 2 } - 9 x$ change from increasing to decreasing?

• A)3
• B)1
• C)4
• D) - 3
• E)2
• F)0
• G) - 2
• H) - 1