Review 9a: Quadratics!!

12. Now name the y-intercept of the following: y=(x-12)(x-2)

• (0, -14)
• (0, 14)
• (0, 24)
• (0, -24)

11. Now name the y-intercept of the following: y=(x+5)(x-4).

• (0, -20)
• (0, 20)
• (0, 1)
• (0, -1)

10. Now name the y-intercept for y=(x-2)(x+8).
* Remember that the y-intercept has an x-coordinate of 0. So it is (0, ?). Plug 0 in for x in the equation and find out the y-coordinate.

• (0, 6)
• (0, -6)
• (0, -16)
• (0, 16)

9. Now name the vertex of y=(x-12)(x-2). 

• (7, 10)
• (7, -25)
• (7, 25)
• (7, -10)

8. Now name the vertex of y=(x+5)(x-4). 

• (1, -13)
• (-1, 4)
• (-.5, -20.25)
• (5, 4)

7. Now name the vertex of y=(x-2)(x+8). 
*Remember the vertex is halfway between the roots. For this problem, add 2+ -8 and divide by 2. You get -3. Now plug -3 back into the equation y=(x-2)(x+8) for x. Find out what the y-coordinate of the vertex.

• (-3, 8)
• (-3, 2)
• (-3, 10)
• (-3, -25)

6. Name the roots for each equation.     y = (x-12)(x-2)

• (0, 12) and (0, 2)
• (-12, 0) and (-2, 0)
• (12, 0) and (2, 0)
• (0, -12) and (0, -2)

5. Name the roots for each equation.     y = (x+5)(x-4)

• (-5, 0) and (4, 0)
• (5, 0) and (-4, 0)
• (0, 5) and (0, -4)
• (0, -5), and (0, 4)

4. Name the roots for each equation.     y = (x-2)(x+8)

• (2, 0) and (8, 0)
• (-2, 0) and (8, 0)
• (2, 0) and (-8, 0)
• (0, -2) and (0, 8)

4e) Find the y-intercept.

• (0, -14)
• (-2, 0)
• (7, 0)
• (2.5, -20)