Find the value of a in y=a(2)^x passing through (3,4)

[racheluckhardt]

algebra 2 help...need it desperately

What law or physics principle is that? Thanks for the help.

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

 

[OlderDan]

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

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

 

[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)?
2) How can this equation help you solve for "a"?
3) Welcome to PF!

 

[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.

Ask if you need more help!