Evaluate and graph an exponential function

Answer Key - Grade 9 Math Worksheet

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

1. 1.

   Milo draws a branching tree with f(x) = 3 · 5^x tips after x rounds. What is f(3)?

   375
2. 2.

   Noah's class phone tree reaches f(x) = 6 · 3^x new families in round x. What is f(4)?

   486
3. 3.

   Ren's math-club rule is g(x) = 75 · 5^x. What is g(-2)?

   3
4. 4.

   Tala's homework rule is h(x) = 6 · 2^x. What is h(-2)?

   3/2
5. 5.

   Zee's map-zoom rule is f(x) = 54 · 3^x. What is f(-3)?

   2
6. 6.

   Esme plots points from a pattern that multiplies by the same factor each step. Which function matches the graph?

   • y = 5x + 5
   • y = 10 · 2^x
   • y = 5 · 2^x
   • y = 2 · 5^x
7. 7.

   Kira studies f(x) = 5 · 2^x. What is the range of f?

   • y ≥ 0
   • all real numbers
   • y > 0
   • y ≥ 5
8. 8.

   Milo graphs f(x) = 6 · 3^x. As x gets more and more negative, the graph gets closer and closer to a line. Which line?

   • y = 6
   • y = 0
   • x = 0
9. 9.

   Noah graphs h(x) = 8 · 2^x. As x gets more and more negative, the graph gets closer and closer to a line. Which line?

   • y = 8
   • x = 0
   • y = 0
10. 10.

    Pia studies f(x) = 4 · 5^x in math club. What is the domain of f?

    • y > 0
    • all real numbers
    • x ≥ 0, because the inputs start at zero