Graphs and Coordinates

• How would you find the midpoint of a line?

  $(x_1+x_2/2 , y_1 +y_2/2)$
• If m_1 and m_2 or perpendicular then what?

  m_1 and m_2 multiply to get -1
• What is the equation of a line?

  $y-y_1=$$m(x-x_1)$
• What is the discriminant?

  Determine the nature of roots
• What is the discriminant formula?

  $b^2-4ac$
• What does it mean if the discriminant is more than 0?

  Two real roots
• What does it mean if the discriminant is equal to 0?

  One real repeated root
• What does it mean if the discriminant is less than 0?

  No real roots