Question

What is a quadratic formula? how can i solve x^2 + 8x + 12 = 0 applying quadratic formula?

Answer 1

there is only one Quadratic Formula.

It allows you to compute the roots of any quadratic equation.

Given the equation ax^2 + bx + c = 0, the roots are given by

x = [-b ± √(b^2 - 4ac)]/2a

Now, you have

x^2 + 8x + 12 = 0

so, the two roots of this equation are

[-8 ± √(64-4*1*12)]/2*1
= [-8 ± √(64-48)]/2
= [-8 ± √16]/2
= [-8 ± 4]/2
= -4 ± 2
= -4+2 or -4-2
= -2 or -6

This can be verified by noticing that

x^2 + 8x + 12 = 0
(x+2)(x+6) = 0
x = -2 or -6