TI-84 Calculator

Find the roots of a polynomial by graphing

Find local maximum and minimum of any graph

Find the value of a derivative at any point

...essentially having the calculator do the HEAVY LIFTING FOR YOU!

Remember: x-intercepts are where y = 0, have ordered pair (x, 0)

Use the function y1 =  $x^2-4x-4$  

Go to the Calculate Menu, and select (2) "Zero"

find the "left bound" by hitting the "<-" until the cursor is left of the first x-intercept and hit "Enter"

find the "right bound" by hitting the "->" until the cursor is right of the first x-intercept and hit "Enter"

"Guess" what the value of x will be 

Your left most x-intercept should be (-0.828, 0)

Let's use a different function for this ...

In place of Y1, use the function $x^3-4x+2$  (check the exponents!)

Go to the "Calculate Menu" and select (3) "Minimum"

For this particular function, the local min is found at the right between 0 and 2.

The process is the same as finding the zeros: Left Bound, Right Bound, Guess.

Just make sure you know which value you are finding, otherwise the calculator will return an "Error"

The local min of this function is (1.155, -1,079)

Let's use a new function...

 Y1 =    $\sqrt{\left(x+2\right)^2+10}$  

Enter the "Calculate" Menu and Select (6) dy/dx

You will be prompted for a value for x. Type in "0" to find the value of the derivative of Y1 at x = 0.