SOLVING QUADRATIC EQUATIONS
A quadratic equation in is an equation that may be written in the standard quadratic form
if . There are four different methods used to
solve equations of this type.
Factoring Method
If the quadratic polynomial can be factored, the Zero Product Property may be used. This property states that when the product of two factors equals zero, then at
least one of the factors is zero.
If and are algebraic expressions, then if and only if or .
Steps to solve quadratic equations by factoring:
1. Write the equation in standard form (equal to 0).
2. Factor the polynomial.
3. Use the Zero Product Property to set each factor equal to zero.
4. Solve each resulting linear equation.
Examples:
A.
1.
2.
3. or
4. or
B.
1.
2.
3.
4.
C.
1.
2.
3. or
4.
or
Square Root Property
This property states: If and are algebraic expressions such that
, then
. This method is used if the form of the equation is:
or
(where represents a constant)
Steps to solve quadratic equations by the square root property:
1. Transform the equation so that a perfect square is on one side and a constant is on the other side of the equation.
2. Use the square root property to find the square root of each side. REMEMBER that finding the square root of a constant yields positive and negative values.
3. Solve each resulting equation. (If you are finding the square root of a negative number, there is no real solution and imaginary numbers are necessary.)
Examples:
1.
2.
3.
1.
2.
3.
1.
2.
3.