How to Write an Exponential Function from a Table

[@ZURUXGM]

Wow I needed this since my teacher literally doesn’t explain anything

[@christian-sr8bk]

Lol

[@360noscopersoof5]

Same mate, she goes: ok everyone so *does question* Ok now you do the rest *is on phone with no shoes*

[@gpetty599]

THANK YOU SO MUCH! You literally explained this in the most concise way possible. Thank you for uploading this!

[@christen2254]

My professor was talking about this and I needed a refresher. Thank you!

[@vlsabah5048]

This video came in clutch

[@savillaruby390]

Thank you so much, I was really struggling with this topic and you explained it in such a clear, concise way. I really appreciate what you do!

[@bhavya5117]

Thankyou so much I was crying over this for an hour

[@indigo6485]

My teacher never fills in gaps and just puts us on desmos for the entire class and when I ask questions hes really big on you figure it out that just causes me emences stress

[@ms.jarosalgebrageometry3359]

I can see how that would be stressful. I glad this video helped.

[@rkt3127]

Thanks I was confused

[@mitzyespana2049]

So what was the final equation?

[@ms.jarosalgebrageometry3359]

f(x) = 4(0.7)^x

[@partypartyyeaa9332]

who else has to teach themselves bc their teacher gives them a small PowerPoint and explains nothing?

[@lynniehill6027]

*Gives you a 5 min span of them basically telling you nothing that has to do with it then just expects you to get it*

[@sondrawilson4430]

My teacher just said search it up to get an understanding of what the a, b, and x were. Also here I am trying to figure it out because I didn't get enough time to ask someone to help me because I'm just beginning this lesson so thanks a lot :). It feels like a lot of pressure was taken off my chest :)

[@pinktacokillah5287]

My table doesnt have a 0 though

[@ms.jarosalgebrageometry3359]

If your table has a 1 and 2, you can go backwards in the table to figure out the 0.

[@alanna-maryquinn1193]

@@ms.jarosalgebrageometry3359 how do i do that?

[@ms.jarosalgebrageometry3359]

@@alanna-maryquinn1193 For example, in this one, b = 0.7 because you multiplied by 0.7. To go backwards (up the table), you divide by 0.7

[@finnymcbites8441]

but how do you assemble the equation after

[@ms.jarosalgebrageometry3359]

Your final equation is f(x) = a*(b)^x , it will also sometimes be written more simply as f(x) = a(b)^x

[@kl4pp3d_78]

@@ms.jarosalgebrageometry3359 thanks!!

[@kl4pp3d_78]

@@ms.jarosalgebrageometry3359 what about the percent? where does it go?

[@ms.jarosalgebrageometry3359]

@@kl4pp3d_78 Are you referring to percent change? If so, it would be 70% change. If it helps, remember that (per)(cent) literrally means "per 100", so you just take the change, 0.7, and multiply it by 100: 0.7*100 = 70 %.

[@Bellasblock]

This video helped me sooo much! Thank you!

[@ms.jarosalgebrageometry3359]

Glad it helped!

[@joeyhensley9870]

@@ms.jarosalgebrageometry3359 pp

[@lynniehill6027]

When your teacher gives you tables that have a different number to multiply by on each row 💀 this was kinda helpful though, thank you!

[@ms.jarosalgebrageometry3359]

The other thing you may want to check is what 'x' values your teacher gives you. In my example, the x's just keep going up by 1 (0, 1, 2, 3, 4). If your x's go up by a different number (for example 0, 1, 2, 4, 6 or something), you may need to fill in the blanks a bit by adding in the rows the table didn't include.

[@lynniehill6027]

@@ms.jarosalgebrageometry3359 no they go up like (1,2,3,4)

[@ms.jarosalgebrageometry3359]

@@lynniehill6027 What are the y or f(x) values of the table?

[@lynniehill6027]

@@ms.jarosalgebrageometry3359 the first table has (12, 15, 19, 24)

[@ms.jarosalgebrageometry3359]

@@lynniehill6027 Yup, so yours is not an exponential function. For your equation, notice how the numbers go up be 3, 4, 5 (because 12 + 3 = 15, 15 + 4 = 19, 19 + 5 = 24). Because the amount you are going up by is going up by the same amount each time, you have a quadratic function. This video (kzbin.info/www/bejne/qInYnoOGosuVlZo&ab_channel=NicoleSimon) will be closer to what you're looking for for your problem.

[@kadinm5521]

thank u i needed this

[@chairwcheese]

Can you please tell me the equation for an exponential function? Thanks

[@ms.jarosalgebrageometry3359]

f(x) = a*(b)^x , it will also sometimes be written more simply as f(x) = a(b)^x. "a" is your starting value (aka where the function is at when x = 0). "b" is your ratio of change (the number you keep multiplying by). Your final answer should have numbers for "a" and "b", but x will stay as a variable. So for example, you could have an equation like f(x) = 3(0.5)^x.

[@bracamontes2607]

Yah but what about if the y row is dividinng. Like -4/-2/-1/ -1/2

[@ms.jarosalgebrageometry3359]

dividing by a number is the same as multiplying by 1 divided by that number, so dividing by two is the same as multiplying by 1/2

[@queena5089]

If f(x) doesn’t decrease or increase by 5e same amount does that mean it’s not exponential?

[@ms.jarosalgebrageometry3359]

Good question. If you are increasing/decreasing by MULTIPLYING or DIVIDING by the same amount each time, it is exponential. If you are increasing/decreasing by ADDING or SUBTRACTING by the same amount each time, it is linear. If it doing neither of these it is neither linear nor exponential. It might be quadratic, cubic, or some other polynomial or pattern.

[@obaidalsuwaidi7141]

Good job

[@elyk666]

Thank you!

[@emeraldstuff2847]

thx

[@canigetauhhhuhuhuh9813]

very helpful, but what if you have different numbers in ur input

[@ms.jarosalgebrageometry3359]

The process would still be the same.

[@ms.jarosalgebrageometry3359]

To find the 'a', look for the y-value when x = 0.

[@ms.jarosalgebrageometry3359]

The find the 'b', look for how much it's multiplying by each time. If you can't figure out the number just by looking at it, you can work backwards by dividing the numbers.

[@lynniehill6027]

@@ms.jarosalgebrageometry3359 what if its a different number each time?

[@ms.jarosalgebrageometry3359]

@@lynniehill6027 If it is not multiplying or dividing by the same number each time, then it is not an exponential function. This means you'll have to check to see if it's a different type of function. For example, if it is adding or subtracting by the same amount each time, it's a linear function. If you notice that the amount it's going up by is going up by the same amount each time, then it is a quadratic function. (If you have a specific question you'd like help with, you can also let me know)

[@carolinehansen00]

Thanks!!!

[@hudsen1]

finally