Graph logarithmic functions

Answer Key - Grade 11 Math Worksheet - Challenge Me

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

1. 1.

   Pia plots points from a log table and joins them with a curve. Which equation matches the graph?

   • y = log₂ (x + 3)
   • y = log₂ (x − 3)
   • y = log₂ x
   • y = 2^(x − 3)
2. 2.

   Tala plots points from a log table and joins them with a curve. Which equation matches the graph?

   • y = log₂ x
   • y = log₂ x − 1
   • y = 2^x − 1
   • y = log₂ x + 1
3. 3.

   Ari swaps the x and y columns of the table for y = 3^x − 1. Which equation gives the new table, the inverse?

   • y = log₃ x − 1
   • y = 1/(3^x − 1)
   • y = log₃ (x − 1)
   • y = log₃ (x + 1)
4. 4.

   Bo swaps the x and y columns of the table for y = 2^(x − 4). Which equation gives the new table, the inverse?

   • y = 1/(2^(x − 4))
   • y = log₂ x + 4
   • y = log₂ (x − 4)
   • y = log₂ x − 4
5. 5.

   Esme graphs y = log₄ x + 3/2. At what value of x does the graph cross the x-axis?

   1/8
6. 6.

   Jun graphs y = log₉ x − 1/2. At what value of x does the graph cross the x-axis?

   3
7. 7.

   Luz graphs y = log₅ (x − 14). At what value of x does the graph cross the x-axis?

   15
8. 8.

   Milo reads the graph of y = log₈ (x + 4). What is y when x = 12?

   4/3
9. 9.

   Pia reads the graph of y = log₂₇ x + 2. What is y when x = 9?

   8/3
10. 10.

    Ren reads the graph of y = log₁₆ (x − 4). What is y when x = 12?

    3/4