Write a quadratic function from three points

Answer Key - Grade 11 Math Worksheet - Building Confidence

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

1. 1.

   Esme's rainbow design on graph paper passes through (3, 20). Its rule is y = ax² + bx + c. Which equation in a, b and c does that point give?

   • 3a + 9b + c = 20
   • 6a + 3b + c = 20
   • 400a + 20b + c = 3
   • 9a + 3b + c = 20
2. 2.

   Jun's kite path passes through (-3, 12). The path is y = ax² + bx + c. Which equation in a, b and c does that point give?

   • -6a − 3b + c = 12
   • 9a − 3b + c = 12
   • -9a − 3b + c = 12
   • -3a + 9b + c = 12
3. 3.

   Milo's bowl design passes through (-5, 30). The design is y = ax² + bx + c. Which equation in a, b and c does that point give?

   • -10a − 5b + c = 30
   • -25a − 5b + c = 30
   • 25a − 5b + c = 30
   • -5a + 25b + c = 30

4. Read this first

   Use the table

   x	-1	0	1
   y	13	8	9

5. 4.

   Noah records three points of a kite's path in the table. The path is y = ax² + bx + c. What is a?

   3
6. 5.

   Pia's rainbow drawing goes through the points in the table. The rule is y = ax² + bx + c. What is a?

   -2
7. 6.

   Ren plots a bowl design from the table. The rule is y = ax² + bx + c. What is a?

   4
8. 7.

   Zee draws a swing's path through the points in the table. The path is y = ax² + bx + c. What is a?

   -3
9. 8.

   Esme copies three points of a design into the table. The rule is y = ax² + bx + c. What is b?

   -3
10. 9.

    Jun's skate ramp goes through the points in the table. The ramp is y = ax² + bx + c. What is b?

    6
11. 10.

    Luz records three points of a kite's path in the table. The path is y = ax² + bx + c. What is b?

    4