Graphing Calculator


How to Use a Graphing Calculator (below, from Kevin Beck @ Sciencing.com)

Basic Graphing Functions

  1. Press the "Y=" button to enter the function screen.
  2. Enter the function (e.g., Y = X2- 4) into one of the lines.
  3. Press "GRAPH." The calculator will draw the function for you.

To find the Y-intercept of a graph that has been drawn:

  1. Press "2nd," then "TRACE" to go to the "CALCULATE" window.
  2. Highlight "value" and press "ENTER."
  3. At the bottom of the screen that appears, enter "0" after "X=." The result will be the Y-intercept and associated X-coordinate.


Quadratic Equations

  1. Press the "Y=" button to enter the function screen.
  2. Enter the function; for example, "−3x2+14x−8."
  3. Press "2nd," then "TRACE" to go to the "CALCULATE" window.
  4. Select whether the vertex is a maximum (as in this example) or a minimum.
  5. Using the arrows, select the LEFT BOUND and the RIGHT BOUND to get the vertex coordinates.
  6. Repeat the process to find the X-intercept or intercepts, if desired. It may be necessary to ZOOM out.


Non-Linear and Linear Regressions

  1. Press "2nd," and then "STAT PLOT." Press "ENTER."
  2. After clearing all functions in "Y=", input data in L1 and L2.
  3. Graph the data points by going to "9: ZOOM STat."
  4. Look at "CALC" and choose a regression from the list.
  5. Choose "9: ZoomSTat" to view data with a regression curve.