GR9 Q1-L1

• Quadratic equation


  A mathematical sentence of the second degree
• Identifying a quadratic equation

  1. Arrange into standard form ax^2 + bx + c = 0

  2. a should not be 0

  3. a is a positive real number
• Parts of a quadratic equation

  • a (quadratic term)
  • b (linear term)
  • c (constant term)
• Quadratic equations


  • x^2 - 5x + 3 = 0
  • x^2 + 4x + 1 = 0
  • 9x^2 - 25 = 0
  • 1/2x^2 + 3x = 0
  • 7x^2 = 1/3x
  • 6x^2 = 9
  • -8x^2 + x = 6
  • 3x^2 - 6x - 10 = 0
  • 2x^2 + 3x + 1 = 0
  • 3x^2 - x + 5 = 0
• If a = 0, the equation is no longer quadratic but linear
• If b = 0, the equation can still be quadratic as long as a and c are not 0
• If c = 0, the equation can still be quadratic as long as a and b are not 0