A function can be illustrated on a graph – points are plotted as coordinates and joined by either a straight line or a smooth curve. A linear function has an equation of the form y = m x + c.

All quadratic functions have the same type of curved graphs with a line of symmetry. The graph of the quadratic function \(y = ax^2 + bx + c \) has a minimum turning point when \(a \textgreater 0 \) ...