Question

Solve for x in the equation x squared minus 12 x + 59 = 0.
x = negative 12 plus-or-minus StartRoot 85 EndRoot
x = negative 6 plus-or-minus StartRoot 23 EndRoot i
x = 6 plus-or-minus StartRoot 23 EndRoot i
x = 12 plus-or-minus StartRoot 85 EndRoot

Answer 1

Use the quadratic formula. For x^2 − 12x + 59 = 0, the discriminant is Δ = 144 − 4·1·59 = −92, so

x = (12 ± √(−92))/2 = (12 ± 2i√23)/2 = 6 ± i√23.

So the correct choice is: x = 6 ± √23 i.