Use the quadratic formula and a calculator to approximate the solution to the nearest tenth.
-$3 x ^ { 2 } + 2 x - 2 = 0$
A) $0.5 , - 1.2$
B) $1.2 , - 0.5$
C) $1.1 , - 2.4$
D) $4.3 , - 5$

Question

Quizplus · Accepted Answer

The quadratic formula is $x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$, where $a = 3$, $b = 2$, and $c = -2$. Plugging these values in gives $x = \frac{-2 \pm \sqrt{(2)^2 - 4(3)(-2)}}{2(3)}$, which simplifies to $x = \frac{-2 \pm \sqrt{4 + 24}}{6}$ or $x = \frac{-2 \pm \sqrt{28}}{6}$. Approximating the solutions gives $x \approx 0.5$ and $x \approx -1.2$.

Use the Quadratic Formula and a Calculator to Approximate the Solution