Determine the Open Intervals on Which the Graph Of $y = - 3 x ^ { 3 } + 8 x ^ { 2 } + 8 x - 5$

question 68

Multiple Choice

Determine the open intervals on which the graph of $y = - 3 x ^ { 3 } + 8 x ^ { 2 } + 8 x - 5$ is concave downward or concave upward.

• A)concave downward on \(( - \infty , \infty )\)
• B)concave downward on \(\left( - \infty , \frac { 8 } { 9 } \right)\) ; concave upward on \(\left( \frac { 8 } { 9 } , \infty \right)\)
• C)concave upward on \(\left( - \infty , - \frac { 8 } { 9 } \right)\) ; concave downward on \(\left( - \frac { 8 } { 9 } , \infty \right)\)
• D)concave downward on \(\left( - \infty , - \frac { 8 } { 9 } \right)\) ; concave upward on \(\left( - \frac { 8 } { 9 } , \infty \right)\)
• E)concave upward on \(\left( - \infty , \frac { 8 } { 9 } \right)\) ; concave downward on \(\left( \frac { 8 } { 9 } , \infty \right)\)

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