What is the Quadratic Equation?
The quadratic equation can be written in different forms.
The standard quadratic equation is in the form:
ax2 + bx + c = 0
Please scroll to the next section of this page to see the free examples.
Standard Quadratic Equation
You will see several questions on quadratics on your algebra test.
A quadratic equation contains a variable such as the x2 term as the highest power.
In other words, an equation is quadratic only when it has a variable that is raised to the power of 2.
Let’s look at our equation again.
ax2 + bx + c = 0
In the equation above, a, b, and c are numbers.
a, b, and c can be fractions or decimals. They do not have to be whole numbers.
a, b, and c can also be imaginary numbers.
Other Forms of the Quadratic Equation
The standard quadratic equation can be re-written if the terms are re-arranged.
The standard quadratic equation can also be re-written if the b or c terms are equal to zero.
However, the a term can never equal zero in a quadratic equation.
We can write the standard form of the equation as follows:
x2 + bx + c = n (when a = 1)
x2 + bx = n (when c = 1)
x2 = n (when b = 0 and c = 0)
Before trying the exercises at the bottom of the page, you should view our posts on quadratic forms and the FOIL method.
Quadratic Expressions
Quadratic equations must contain an equals sign.
A quadratic expression is the part of the quadratic equation without the equals sign.
So, ax2 + bx + c is an example of a quadratic expression.
In other words, on one side of the equation, a quadratic equation includes a quadratic expression.
You should also view our posts on the quadratic formula and quadratic expressions.
Solving Quadratic Equations
We look at how to solve quadratic equations in our post entitled “Solving Quadratic Equations.”
Click on the following links for: