Question

What are the roots of this function? f(x) = x2 – 8x + 12 A) {2, 6} B) {8, 12} C) {-3, -4} D) {-4, -4}

Answer 1

Answer:

A.

Step-by-step explanation:

delta = $b^{2} - 4ac = (-8)^{2}-4*1*12 = 64 - 48 = 16$

$x_{1} = \frac{b-\sqrt{delta}}{2a} = \frac{8+4}{2} = 6$  

$x_{2} = \frac{b+\sqrt{delta}}{2a} = \frac{8-4}{2} = 2$