Exponential and Logistic Modeling on a Graphing Calculator

Key Questions

How do I find an exponential model of the form $y = a e^{k t}$ $y = ae^(kt)$ on a TI-84?

I don't think you can make a model with the $e$ $e$ or the two $k$ $k$ and the $t$ $t$ . However, you can make a $y = a b^{x}$ $y=ab^x$ model using the Exponential Regression key. To use this, go to STAT $\to$ $->$ CALC $\to$ $->$ and scroll down until you see "ExpReg".

Then, if you have data entered into your STAT key, then you'll get a model for that.

Hope that helps :)

Darshan Senthil · 1 · Feb 19 2015
How could the graph of an exponential function be used to determine an $a$ $a$ value?

I assume you mean the "A" as in the initial value of $y = A e^{r t}$ $y=Ae^(rt)$ ? $y$ $y$ -intercept

The "a" value occurs at $t = 0$ $t=0$ , so $e^{0} = 1$ $e^0=1$ , therefore $y = A$ $y=A$ is $(0, A)$ $(0,A)$ , the $y$ $y$ -intercept.

David Britz · 1 · Apr 21 2015
What characteristics are identified from the graph of an exponential function?

Consider the exponential function $f (x) = a^{k x}$ $f(x)=a^(kx)$ , where $a$ $a$ and $k$ $k$ are constant, $a, k in RR$ .

I prepared a dynamic plot that can be used to study the properties of the exponential function as $a$ and $k$ take various values.

Please use the provided sliders to change the values of the parameters $a$ and $k$ and see what happens to the graph of the function.

Pay particular attention to the cases when $0 < a < 1$ and $a > 1$ . For each of these cases, see what happens when $k<0$ and $k>0$ .

https://www.desmos.com/calculator/g3k7pyi7dz

Alex Boroda · 1 · Jun 3 2015
How do I create a logistic model of population growth on a TI-83?

Answer:

See the video from YouTube.

Explanation:

The following steps shown on the TI-84 is the same as the steps found on a TI-83.

Andy Y. · 1 · May 24 2017