A quadratic function is a polynomial function of degree 2 which can be written in the general form,
f(x)=ax2+bx+c
The graph of a quadratic function is a parabola, and its parts provide valuable information about the function.
- The sign of the coefficient of the quadratic function affects whether the graph opens up or down. If a<0, the graph opens downwards and if b, then the graph opens upwards.
- Each parabola is symmetric about a vertical line called the axis of symmetry. This vertical line goes through the vertex.
- All quadratic functions of the form f(x)= ax2+bx+ c have parabolic graphs with y -intercept (0,c). However, not all parabolas have x -intercepts.