Example 3 + up/down test

up/down test

• opens upwards because a is Positive
  
•  opens downward because a is Negative

Example 3

1. a) y= x^2 + 3x + 4 
   • opens upwards because a is Positive
     
2. b) y = -3x^2 + 5x
   
   •  opens downward because a is Negative
3. c) y = 2x - x^2 + 6
   
   •  opens downward because a is Negative