<Dd> a x 2 + b x + c = a (x − − b + b 2 − 4 a c 2 a) (x − − b − b 2 − 4 a c 2 a). (\ displaystyle ax ^ (2) + bx + c = a \ left (x - (\ frac (- b+ (\ sqrt (b ^ (2) - 4ac))) (2a)) \ right) \ left (x - (\ frac (- b - (\ sqrt (b ^ (2) - 4ac))) (2a)) \ right).) </Dd> <P> In the special case b = 4ac where the quadratic has only one distinct root (i.e. the discriminant is zero), the quadratic polynomial can be factored as </P> <Dl> <Dd> a x 2 + b x + c = a (x + b 2 a) 2 . (\ displaystyle ax ^ (2) + bx + c = a \ left (x+ (\ frac (b) (2a)) \ right) ^ (2).) </Dd> </Dl> <Dd> a x 2 + b x + c = a (x + b 2 a) 2 . (\ displaystyle ax ^ (2) + bx + c = a \ left (x+ (\ frac (b) (2a)) \ right) ^ (2).) </Dd>

What is meant by the solution to a quadratic equation