Evaluate $\sqrt { b ^ { 2 } - 4 a c }$ for the given values of a, b, and c, and simplify.
-$a = 4 , b = - 2$, and $c = 7$
A) $3 \mathrm { i } \sqrt { 6 }$
B) $6 \mathrm { i } \sqrt { 3 }$
C) $6 \sqrt { 3 }$
D) $- 6 \sqrt { 3 }$

Question

Quizplus · Accepted Answer

The expression $\sqrt { b ^ { 2 } - 4 a c }$ is part of the quadratic formula. Substituting $a = 4$, $b = -2$, and $c = 7$ gives $\sqrt { (-2) ^ { 2 } - 4 \cdot 4 \cdot 7 } = \sqrt { 4 - 112 } = \sqrt { -108 }$. Simplifying $\sqrt { -108 }$ gives $6 \mathrm { i } \sqrt { 3 }$, where $i$ is the imaginary unit.

Evaluate b2−4ac\sqrt { b ^ { 2 } - 4 a c }b2−4ac​

Evaluate $\sqrt { b ^ { 2 } - 4 a c }$