Given the functions

f(x) = x2 and g(x) = cos(x)

graph the functions f, g, f+g for  x  in the interval  [-p, p] using the TI-85 graphing calculator.


[Press here to see animation again!]

  1. If you are not familiar with the graphing of functions on the TI-85, then first read the Initial Setup page from Little's Basic Guide to the TI-85.
  2. Press the GRAPH key and then pick y(x)= by pressing the F1 key.
  3. If necessary, keep pressing F4 key until only y1= appears on the screen.
  4. Type in

    and press the ENTER key.

  5. Type in
    cos x

    and press the ENTER key.

  6. Type in

    y1 + y2

    and press the ENTER key.
    IMPORTANT: Both of these y's must be lower case.

  7. The range settings for the graph above is  [-p, p] × [-1, 10].
  8. Note that the graphs of the functions are plotted in the order in which they are entered above. You can plot only one or two of the graphs by using the SELCT key on the y(x)= screen.