Exponential Functions

Complex numbers, rational functions, logarithms, sequences and series, matrix operations, etc.
Eszebel
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Joined: Sun Mar 27, 2011 5:52 pm
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Exponential Functions

So hopefully I'm posting this in the right area and all that...

I missed a day of trig class and don't understand how to do several kinds of problems relating to exponential functions. I have a test tomorrow, so I really need to figure how to solve them.

Here's an example...

1. Write an exponential equation, y = ab ^ x, for each of the following sets of points:
a) (3, 550) and (5, 1450)
b) (2, 300) and (20, 3500)

Thank you in advance for your help!

maggiemagnet
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Joined: Mon Dec 08, 2008 12:32 am
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Re: Exponential Functions

1. Write an exponential equation, y = ab ^ x, for each of the following sets of points:
a) (3, 550) and (5, 1450)
b) (2, 300) and (20, 3500)
For (a), plug each point into the equation. This will give you:

$550=ab^3$
$1450=ab^5$

This is a system of non-linear equations. What do you get if you divide the second equation (left-hand side by left-hand side, right-hand side by right-hand side) by the first equation? You should end up with something that you can solve for the value of 'b'. Then you can solve either of the equations for 'a'.

Eszebel
Posts: 2
Joined: Sun Mar 27, 2011 5:52 pm
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Re: Exponential Functions

...oh. I should've been able to figure that out xD Thanks!