MathDB
what x's make y real?

Source:

March 25, 2006
quadraticsalgebraquadratic formula

Problem Statement

If xx is a real and 4y2+4xy+x+6=04y^2+4xy+x+6=0, then the complete set of values of xx for which yy is real, is:
(A) x2 or x3(B) x2 or x3(C) x3 or x2\text{(A)} \ x\le -2~\text{or}~x\ge3 \qquad \text{(B)} \ x\le 2~\text{or}~x\ge3 \qquad \text{(C)} \ x\le -3 ~\text{or}~x\ge 2 \text{(D)} \ -3\le x \le 2\qquad \text{(E)} \ \-2\le x \le 3