Features of a parabola from its graph or its equation

Answer Key - Grade 9 Math Worksheet - Building Confidence

Circle the best answer, or write your answer on the line.

1. Read this first

   Use the table

   input x	output y
   -1	0
   0	-3
   1	-4
   2	-3
   3	0
   4	5
   5	12

2. 1.

   Jun records a table for a skate ramp curve. What is the axis of symmetry? Write the number after x =.

   1
3. 2.

   Luz records a table for a bowl design (the bowl is for slime). What is the axis of symmetry? Write the number after x =.

   -2
4. 3.

   Milo records a table for a swing's path. What is the axis of symmetry? Write the number after x =.

   2
5. 4.

   Noah graphs a valley on a hiking map and keeps a table. Where does the graph cross the x-axis? Type both x-values, smaller first, with a comma between.

   -2, 4
6. 5.

   Pia graphs the roof of a play tent and keeps a table. Where does the graph cross the x-axis? Type both x-values, smaller first, with a comma between.

   -2, 3
7. 6.

   Ren graphs a cereal bowl and keeps a table (the cereal stays out). Where does the graph cross the x-axis? Type both x-values, smaller first, with a comma between.

   -5, -1
8. 7.

   Tala graphs a bike ramp and keeps a table. Where does the graph cross the x-axis? Type both x-values, smaller first, with a comma between.

   -1, 3
9. 8.

   Bo graphs a bowl, y = 2x² + 12x + 13, with vertex (-3, -5). Does the graph have a maximum or a minimum, and what is it?

   • A maximum of -5
   • A minimum of -3
   • A minimum of -5
10. 9.

    Esme graphs a swing path, y = x² - 8x + 10, with vertex (4, -6). Does the graph have a maximum or a minimum, and what is it?

    • A minimum of -6
    • A minimum of 4
    • A maximum of -6
11. 10.

    Jun graphs a frog's hop, y = -3x² - 6x + 4, with vertex (-1, 7) (a personal best). Does the graph have a maximum or a minimum, and what is it?

    • A minimum of 7
    • A maximum of -1
    • A maximum of 7