Graph y = ax^2 + bx + c, and match equations, tables and graphs

Answer Key - Grade 9 Math Worksheet

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

1. 1.

   Esme graphs a skate ramp with y = x² - 6x + 5. What is the vertex? Type its x-value, then its y-value, with a comma between.

   3, -4
2. 2.

   Jun graphs a cereal bowl with y = 2x² - 12x + 11. What is the vertex? Type its x-value, then its y-value, with a comma between.

   3, -7
3. 3.

   Luz graphs a basketball shot with y = -2x² + 16x - 25 (nothing but net, on paper). What is the vertex? Type its x-value, then its y-value, with a comma between.

   4, 7
4. 4.

   Milo draws a lake bottom on a map with y = x² + 10x + 22. What is the vertex? Type its x-value, then its y-value, with a comma between.

   -5, -3
5. 5.

   Noah has four graph cards and the equation y = -x² + 2x + 3. Which graph matches the equation?

   • Opens down, vertex (1, 4), crosses the y-axis at 3
   • Opens up, vertex (1, 4), crosses the y-axis at 3
   • Opens down, vertex (0, 3), crosses the y-axis at 3
   • Opens down, vertex (-1, 0), crosses the y-axis at 3
6. 6.

   Pia sorts graph cards for y = x² + 4x - 5. Which graph matches the equation?

   • Opens up, vertex (-2, -9), crosses the y-axis at -5
   • Opens down, vertex (-2, -9), crosses the y-axis at -5
   • Opens up, vertex (0, -5), crosses the y-axis at -5
   • Opens up, vertex (2, 7), crosses the y-axis at -5
7. 7.

   Ren sorts graph cards for y = 2x² + 8x - 3 (one card has a juice stain). Which graph matches the equation?

   • Opens down, vertex (-2, -11), crosses the y-axis at -3
   • Opens up, vertex (0, -3), crosses the y-axis at -3
   • Opens up, vertex (2, 21), crosses the y-axis at -3
   • Opens up, vertex (-2, -11), crosses the y-axis at -3
8. 8.

   Tala matches y = -x² - 6x - 5 to a graph of a ball's toss. Which graph matches the equation?

   • Opens down, vertex (0, -5), crosses the y-axis at -5
   • Opens up, vertex (-3, 4), crosses the y-axis at -5
   • Opens down, vertex (-3, 4), crosses the y-axis at -5
   • Opens down, vertex (3, -32), crosses the y-axis at -5
9. 9.

   Zee's table for a fountain sketch, y = x² + 2x - 5, has the row 3 | 10. Another input gives the same output. What is that input?

   -5
10. 10.

    Esme's table for a bowl, y = 2x² + 4x - 3, has the row 2 | 13. Another input gives the same output. What is that input?

    -4