byeeee:

Which of the following exponential functions goes through the points (1, 12) and (2, 36)? f(x) = 4(3)−x f(x) = 3(4)−x f(x) = 3(4)x f(x) = 4(3)x

6 months ago
dude:

Right off the bat, lets look at the points. Do they go up or down?

6 months ago
byeeee:

up

6 months ago
dude:

So we can eliminate $$f(x) = 4(3)^{−x}$$ and $$f(x) = 3(4)^{−x}$$

6 months ago
byeeee:

yeah

6 months ago
dude:

To check which one is right we can substitute each point into the equations (If you dont have access to a graphing calculator) Ex. (To check for answer choice D) $$f(x)=4(3)^x=>~~12=4(3)^1$$ and $$36=4(3)^2$$ If you do it should look something like this https://www.desmos.com/calculator/xvcyxstsha

6 months ago
byeeee:

ohh okay

6 months ago
byeeee:

hm

6 months ago
byeeee:

now what?

6 months ago
dude:

Do can you use graphing calculators?

6 months ago
byeeee:

no i can't

6 months ago
dude:

$$\color{#0cbb34}{\text{Originally Posted by}}$$ @dude To check which one is right we can substitute each point into the equations (If you dont have access to a graphing calculator) Ex. (To check for answer choice D) $$f(x)=4(3)^x=>~~12=4(3)^1$$ and $$36=4(3)^2$$ $$\color{#0cbb34}{\text{End of Quote}}$$ Then let's solve for these $$12=4(3)^1$$ $$36=4(3)^2$$

6 months ago
byeeee:

im sorry i have to go now thanks for everything you've helped with ill be on later bye!

6 months ago
dude:

Alright

6 months ago
byeeee:

@dude hey could you help?

6 months ago
byeeee:

nvm i think my answer is D thanks for everything though!

6 months ago