# What is a Quadratic Equation?

1. A quadratic equation is a polynomial equation of the second degree.
2. A quadratic equation has only one variable
3. The highest power of the variable is 2.
Example of Quadratic Equation
The followings are some examples of quadratic equations
• $$2{x^2} + 3x + 4 = 0$$
• $${t^2} = \frac{2}{5}$$
• $$y(6y - 3) = 5$$
• $$a - 3y + 2{y^2} = 2$$ where a is a constant.
Example of Non Quadratic Equation
• $$2x + 1 = 0$$, (Reason: The highest power of x ≠ 2.)
• $$2{x^3} + 1 = x$$, (Reason: The highest power of x ≠ 2.)
• $${t^2} + \frac{5}{t} = 3$$, (Reason: The present of the term $$\frac{5}{t}$$.)

Example 1