How To Graph Parabolas On A TI-84 Calculator

The equation of a parabola is a second-degree polynomial, also known as a quadratic function. Scientists model many natural processes with parabolic curves. For instance, in physics, the equation of projectile motion is a second-degree polynomial. Use a TI-84 graphing calculator to draw parabolas quickly and accurately. With a TI-84 calculator, you do not have to convert the equation of the parabola from standard form to vertex form, or vice versa, in order to plot the function.

Step 1

Press the "Y=" key to open the function input menu on the TI-84.

Step 2

Enter the equation of the parabola in the field marked "Y1." For example, if you have an equation of a parabola in standard form such as 3x^2 + 2x + 7, enter the equation using the keys for numbers, the variable x and operation symbols. If you have an equation of a parabola in vertex form such as 4(x-3)^2 – 8, enter the equation using the number, variable, operation and parentheses keys.

Step 3

Press the "Graph" key to generate the curve on your TI-84 calculator's screen.

Step 4

Press the "Window" key to access the window size menu and adjust the viewing window as necessary. For example, the parabola 3x^2 + 2x + 7 is best viewed in a window in which Xmin = 0, Xmax = 20, Ymin = -10 and Ymax = 10. The default window settings on the TI-84 are Xmin = -10, Xmax = 10, Ymin = -10 and Ymax = 10.