Exponential Funcitons

  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. 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. HallsofIvy

    HallsofIvy 40,556
    Staff Emeritus
    Science Advisor

    However, the graph of y= Cax, passing through (1,6) and (3,24) doesn't cross the y-axis anywhere near 1/2!
     
  5. Gokul43201

    Gokul43201 11,141
    Staff Emeritus
    Science Advisor
    Gold Member

    It crosses at y=3/2.
     
  6. 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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