We can use the quadratic formula to solve any
quadratic equation. Given the standard
form of a quadratic equation, 
, the quadratic
formula al lows us to find all
solutions . The formula is:
The radicand of the formula provides information about the
solutions. If the radicand is
positive , the equation has 2 real solutions . If the radicand is zero , the
equation has 1 real
solution. If the radicand is negative , the equation has 2 imaginary solutions.
This
information is useful when graphing quadratic equations.
