Question

I'm not familiar

Answer 1

Looks like instructions for computing the value of a derivative on one of the TI graphing calculators. I haven't used one of these in a long time (TI-84 series), so bear with me as I'm working from very rusty memory:

(1) Press the ` Y = ` button. This takes you to the function input screen.

(2) Type your function \(f(x)\) in the ` Y1 = ` field.

(3) Press ` HOME `.

(4) Press ` MATH ` and ` 8 `.

This selects the ` nDeriv ` function. Your home screen should say something like ` nDeriv( `. This function takes three arguments: the function \(f(x)\) you want to use, the variable of differentiation, and the value of the independent variable for which you want to compute the derivative.

(5) You could fulfill the first argument requirement by typing \(f(x)\), or, if it's particularly long or hard to remember, you can press the ` VARS ` button, navigate to the ` Y-VARS ` menu, and select ` 1 : Function... `. You should see a list of variables ` Y1 ` to ` Y8 `, or something similar. Select ` Y1 `. This variable refers to the function \(f(x)\) you typed in the second step.

At this point your home screen should say ` nDeriv( Y1 `.

(6) Follow up ` Y1 ` with a comma, then press the ` X, T, Theta, n ` button, which should place the proper independent variable.

You should see ` nDeriv( Y1, X `.

(7) Add a comma, then type in the number for the point you want to use, which I'll denote with #.

You should see ` nDeriv( Y1, X, # `.

(8) Finally, close the parentheses and press ` ENTER `.

Answer 2

Actually, correction to step (3). There is no ` HOME ` button. You can get to the home screen by pressing ` 2ND ` followed by ` MODE ` (the ` QUIT ` option).