Solve the equation using the quadratic formula.
-$$4 x ^ { 2 } + 12 x + 2 = 0$$
A) $\left\{ \frac { - 3 - \sqrt { 7 } } { 2 } , \frac { - 3 + \sqrt { 7 } } { 2 } \right\}$
B) $\left\{ \frac { - 3 - \sqrt { 11 } } { 2 } , \frac { - 3 + \sqrt { 11 } } { 2 } \right\}$
C) $\left\{ \frac { - 12 - \sqrt { 7 } } { 2 } , \frac { - 12 + \sqrt { 7 } } { 2 } \right\}$
D) $\left\{ \frac { - 3 - \sqrt { 7 } } { 8 } , \frac { - 3 + \sqrt { 7 } } { 8 } \right\}$

Question

Quizplus · Accepted Answer

The quadratic formula is $\frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$. For $4x^2 + 12x + 2 = 0$, $a = 4$, $b = 12$, and $c = 2$. Plugging these into the formula gives $\frac{-12 \pm \sqrt{12^2 - 4(4)(2)}}{2(4)} = \frac{-12 \pm \sqrt{144 - 32}}{8} = \frac{-12 \pm \sqrt{112}}{8} = \frac{-12 \pm 4\sqrt{7}}{8} = \frac{-3 \pm \sqrt{7}}{2}$.

Solve the Equation Using the Quadratic Formula 4x2+12x+2=04 x ^ { 2 } + 12 x + 2 = 04x2+12x+2=0

Solve the Equation Using the Quadratic Formula $4 x ^ { 2 } + 12 x + 2 = 0$