Use a Graphing Calculator to Find the Coordinates of the Turning

Multiple Choice

Use a graphing calculator to find the coordinates of the turning points of the graph of the polynomial function in the
indicated domain interval. Give answers to the nearest hundredth.
- $$f ( x ) = x ^ { 3 } + 8 x ^ { 2 } - 21 x - 108 ; [ 1,2 ]$$

A) $( 0,12 )$
B) $( 3.50 , - 40.62 )$
C) $( - 6.42,91.94 )$
D) $( 1.09 , - 120.09 )$