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Exponential Funcitons

  1. Jun 22, 2004 #1
    I have no idea how to do this problem or where to even start: Find the exponential function f(x) = Ca^x who’s graph is given. The graph has a concave up line, that intersects the y-axis at what looks like ½ (no exact intersection is given) and has the two points (1,6) and (3,24).
  2. jcsd
  3. Jun 22, 2004 #2
    That the point (1, 6) lies on the graph means that f(1) = 6. But f(x) = Ca^x, so f(1) = Ca^1 = Ca = 6. You can find a similar equation using the other point. You now have two equations and two unknowns. Can you take it from there?
  4. Jun 23, 2004 #3


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    However, the graph of y= Cax, passing through (1,6) and (3,24) doesn't cross the y-axis anywhere near 1/2!
  5. Jun 23, 2004 #4


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    It crosses at y=3/2.
  6. Jun 23, 2004 #5
    That helps a lot, thank you. Sorry about the ½ thing, didn’t do a very good job of eyeballing it.
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