Introduction to exponential functions

Practice sheet

Fresh questions from the whole chapter, to do on paper.

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  1. A table gives x=0,1,2,3x = 0, 1, 2, 3 and y=4,12,36,108y = 4, 12, 36, 108. What kind of relationship is it?
    1. Exponential: yy is multiplied by 3 at each step
    2. Linear: yy goes up by 8 at each step
    3. Neither
  2. An exponential function has g(0)=9g(0) = 9 and g(1)=18g(1) = 18. Find g(3)g(3).
  3. f(x)=57x+380f(x) = 57x + 380 and g(x)=1.04xg(x) = 1.04^x. For very large xx, which is greater?
    1. gg: exponential growth eventually overtakes linear growth
    2. ff: it is greater now and grows faster
    3. They stay about equal
  4. An arithmetic sequence has a1=14a_1 = 14 and common difference 2. Find a43a_{ 43 }.
  5. In an arithmetic sequence, a4=28a_{ 4 } = 28 and a9=68a_{ 9 } = 68. Find the common difference.
  6. What kind of sequence is 3,6,12,24,…3, 6, 12, 24, \dots?
    1. Geometric, with ratio 2
    2. Arithmetic
    3. Neither
  7. A geometric sequence has a1=3a_1 = 3 and ratio 3. Find a4a_{ 4 }.
  8. Find the common ratio of the geometric sequence 8,32,128,…8, 32, 128, \dots
  9. Write a formula for ana_n, starting at n=1n = 1: 2,8,32,…2, 8, 32, \dots
  10. Evaluate 365236^{ \frac{ 5 }{2} }.
  11. Evaluate 125−23125^{ -\frac{ 2 }{3} }.
  12. A culture starts with 7 grams of algae. Each week, the amount is multiplied by 3. How many grams are there after 3 weeks?