Chapter 9 - Quadratics and quadratic equations

• section 9.1 - In this section we introduce quadratic expressions, quadratic equations, quadratic functions and parabolas.
  
  
• section 9.2 - In this section we explain the “completing the square” method, a versatile method that is the basis for factoring any quadratic trinomial and solving any quadratic equation.
  
  
• section 9.3 - In this section we show how the completing-the-square method can be used to factor any quadratic trinomial.
  
  
• section 9.4 - In this section we show how to solve quadratic equation by four different methods:
  • graphing
  • factoring
  • completing the square
  • using the quadratic formula