If the quadratic has no linear, or first-degree term (i.e. *b* = 0),
then it can be solved by isolating the *x*^{2} and taking square
roots of both sides:

_{}

_{}

_{}

_{}

- You need both the
positive and negative roots because
_{}, so*x*could be either positive or negative. - This is only going to
give a real solution if either
*a*or*c*is negative (but not both)