# Algebra help

1. May 16, 2005

### racheluckhardt

algebra 2 help...need it desperately

does anyone know algebra 2, i need to know how to complete this equation...
an expotential function of the form y=a(2)^x passes through the point (3,4). Find the value of a. choices a)2 b)1/2 c)3 d)3/4

2. May 16, 2005

### OlderDan

Substitute the values in for x and y and solve for a.

3. May 16, 2005

### arildno

Hi, rachel:
Saying that the graph passes through (3,4), means that the following equation holds:
$$4=a*2^{3}$$
1) Do you see why this equation must hold if the graph is to go through (3,4)?
3) Welcome to PF!

4. May 16, 2005

### z-component

An important concept here is the equality between the two expressions in this equation. The expressions on each side of the equal sign must hold the same value, unless you get into other situations (however this one does have a solution). In this example, y is equal to a(2)^x, which is 4=a(2)^3. The object is finding the value for "a" that will make that expression equal to 4.

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