Sharp EL9900C EL-9900C - Page 97

Chapter 6: Advanced Graphing Features - Advanced Keyboard 2. Graphing Parametric Equations A two-dimensional parametric equation assumes that both X and Y are represented by functions in a third variable T. When set in parametric graphing mode, the calculator automatically sets up the Graph Equation Entry screen to take one set of X and Y per each graph, with the equation's right side variable to be set as "T". Note: Example • Draw a graph: x(t) = 16cos(t), y(t) = 9sin(t). 1. Press @ ; to enter the SETUP menu. 2. Press E to select E COORD, then 2 to select 2 Param. Be sure that the other settings are as shown on the right. To exit the SETUP menu, press C. 3. Press Y to go to the Graph Equation Entry window. 4. Enter 16cos(t) for X1T=. Press E when done entering. 5. Enter 9sin(t) for Y1T=. Press E when done entering. The right side variable is automatically set to "T". When the X key is pressed within the Graph Equation Entry window, it will enter the variable "T". 6. Press G to draw the graph. 7. If the graph line extends beyond the screen, press Z and select A ZOOM then 1 AUTO. Use 3 IN or 4 OUT of the A ZOOM to adjust the drawing size. You can also set the drawing size in the WINDOW menu by determining the maximum and minimum values of T, X and Y. 87