Determine the roots of the quadratic equation by completing the square. Solve for exact solutions and approximate solutions. Check your solutions.

Y=x2-6x-12

1 answer

x^2-6x - 12
(x^2-6x+9) - 12-9
(x-3)^2 - 21

so, setting

(x-3)^2 - 21 = 0
(x-3)^2 = 21
x-3 = ±√21
x = 3±√21