Question 1085952
Use the discriminant b^2 - 4ac.


a = 2, b = k, c = 6


Set discriminant to 0 and solve for k.


k^2 - 4(2)(6) = 0


k^2 - 8(6) = 0


k^2 - 48 = 0


k^2 = 48


sqrt{k^2} = sqrt{48}


k = sqrt{16}•sqrt{3}


k = 4•sqrt{3}, k = -4•sqrt{3}


The negative k value is -4•sqrt{3}.