lesson 2

• What is Discriminant?


  Discriminant is used to define roots
• What is the nature of the roots if the discriminant is negative?

  Imaginary or no real root
• What represents the discriminant in the quadratic equation?

  b² - 4ac
• which discriminant value characterizes the real, rational, and equal roots of a quadratic equation?

  0
• what represents the sum of the roots ax² + bx + c = 0 ?

  -b

  a

  negative b, over a
• the sum of the roots

  x² - 10x + 25 = 0 is 10

  what is the product of the roots?

  25
• what is the product of the roots of a quadratic equation

  x² - 4x = 0 ?

  0
• what is the value of the discriminant in x² - 4x = 0?

  0
• which of the following equations is written in standard form?

  • y( y + 3 ) = 0

  • t² - 3 (t + 2) = 0

  • 2d² + 10d + 8 = 0

  • (w + 1)² - 2x + 3 = 0

  • 2d² + 10d + 8 = 0

  because it's on second degree and it has 4 terms and it is equal to zero, therefore it is written on standard form
• what equation can be used to determine the quadratic equation given its roots?

  x² - (r¹ + r²)x + (r¹)(r²) = 0
• the roots of the quadratic equation is 2 and 3. If the product of the roots is 6, what is the sum of the roots?

  5

  because product means multiply, that's why it's equal to 6

  and sum means added that's why it's 5

  roots : 2 and 3

  product: 2 × 3 = 6

  sum: 2 + 3 = 5
• in transforming into standard form, what must be considered first?


  use foil method in simplifying expressions
• sum

  addition
• difference

  subtraction
• product


  multiplication
• quotient 


  division