Quadratic graph lines are U- or Ո-shaped, which is called a parabola. A linear graph can be drawn using only three points. A quadratic graph is a curve, so more points are plotted to support accuracy.
Simultaneous equations like 𝒚 = 2𝒙 - 1 and 𝒚 = 𝒙 + 1 can be represented graphically. To solve the equations graphically, the two lines 𝒚 = 𝒙 + 1 and 𝒚 = 2𝒙 - 1 are drawn on the same diagram.