It's a quadratic function if x (the independent variable) appears with a square (but not with a higher or lower power).Originally Posted byShynita Matthews

Example: y = 1 + 3x^2 is quadratic (I'm using ^2 to indicate the squaring, just as you would do it on a TI-86). y = x^3 - 4x^2 is not a quadratic function (it also has a third order term). y = 3x + 4 isn't quadratic either.

Hope this helps. This is Algebra I I guess? My son just did this 2 classes ago in his math class.