Sharp EL9900C EL-9900C - Page 74

Chapter 4: Basic Graphing Features - Basic Keyboard • 22 kinds of variables (characters), A to Z except for R, T, X, and Y can be used for the substitution feature. • Up to seven variables (characters) can be used for one equation. (If the equation contains more than seven variables (characters), up to seven characters from the top of the equation are determined as variables and subsequent characters are ignored.) • If you attempt to execute an equation containing no variables, the substitution feature becomes invalid and the error message, "NO VARIABLE", appears on the screen. • To input the equation, there are the following two methods after Y has been pressed. After the equation has been input, the same operations apply to subsequent steps. Example Substitute numeric values under the conditions that "Y1 = AX2 + BX + C" and "Y2 = AX" have been input. Equation Entry screen The cursor pointer is located at Y1. Drawing of both graphs Y1 and Y2 is valid. 1. Press @ ,. The substitution feature screen will appear. The equation on which the cursor pointer is located and its variables are displayed on the right of the screen. If variables (characters) contain no values, the graph is not drawn. If independent memories A to C contain any numeric values, the graph is drawn based on these values. * If the equation (in this example, Y1) on which the cursor is located contains no variables, the substitution feature screen will not appear. 64