SOLUTION: Write an exponential function whose graph passes through each pair of points for: (1,5)(2,7)

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Question 880493: Write an exponential function whose graph passes through each pair of points for: (1,5)(2,7)
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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Write an exponential function whose graph passes through each pair of points for: (1,5)(2,7)
Using the exponential function: f(x) = a^x,
Find a relationship
a%5E1%2Fa%5E2 = 5%2F7
Cancel a
1%2Fa = 5%2F7
5a = 7
a = 7/5
a = 1.4
Find what exponent of 1.4 will give you 5
1.4^x = 5
x = ln%285%29%2Fln%281.4%29
x = 4.78327
:
Write an equation from this
f%28x%29+=+1.4%5E%28%28x%2B3.78327%29%29
using a calc
when x=1; f(x) = 5
when x=2, f(x) = 7
:
+graph%28+300%2C+200%2C+-2%2C+5%2C+-5%2C+10%2C+1.4%5E%28x%2B3.78327%29%29+