Use the zero or root feature of a graphing utility to approximate the zeros of $f ( x ) = 2 x ^ { 3 } + 8 x ^ { 2 } - 5 x - 7$ accurate to the nearest thousandth.
A)x = -4.692
B)x = -8.492,-0.695,1.186
C)x = -3.575
D)x = -4.388,-0.720,1.108
E)x = -3.910,-0.763,1.173

Question

Use the zero or root feature of a graphing utility to approximate the zeros of $f ( x ) = 2 x ^ { 3 } + 8 x ^ { 2 } - 5 x - 7$ accurate to the nearest thousandth.
A)​x = -4.692
B)​x = -8.492,-0.695,1.186
C)​x = -3.575
D)​x = -4.388,-0.720,1.108
E)​x = -3.910,-0.763,1.173

Quizplus · Accepted Answer

The zeros of the polynomial can be found using a graphing utility's zero or root feature, which will show where the function crosses the x-axis. The correct zeros, rounded to the nearest thousandth, are -4.388, -0.720, and 1.108, as these values are where the function $f(x) = 2x^3 + 8x^2 - 5x - 7$ intersects the x-axis.

Use the Zero or Root Feature of a Graphing Utility f(x)=2x3+8x2−5x−7f ( x ) = 2 x ^ { 3 } + 8 x ^ { 2 } - 5 x - 7f(x)=2x3+8x2−5x−7

Use the Zero or Root Feature of a Graphing Utility $f ( x ) = 2 x ^ { 3 } + 8 x ^ { 2 } - 5 x - 7$