Quit Please select 1-4 or Q: Change equation With the main menu displayed, press <1>, for "Change equation". The screen will clear and the following will appear : Previous equation y = x^2 This line tells you the previous equation plotted. When you first start this will always be set to y = x^2, but will change when you enter another equation. Please enter the value of A, where y = A( x + b )^2 + c orfor default of 1 : -.07 This value determines the shape of the graph. A negative value will turn it upside down (-1, -23, -4.5) and a positive value will make it upright (1, 13, 8.7). A large value will make it thin (5, -16, 9.5), while a small value will make it fat (.3, -.07, .07). Pressing will set A to its default value of 1. Pressing will give A its previous value. Please enter the value of B, where y = -0.07( x + B )^2 + c or for default of 0 : -2 This value determines the graph's X position. A negative value (-2, -5, -.5) will move the graph to the right. A positive value (4, 8, 3.5) will move the graph to the left. Pressing will set B to its default value of 0. Pressing will give B its previous value. Please enter the value of C, where y = -0.07( x - 2 )^2 + C or for default of 0 : 9 This value determines the graph's Y position. A negative value (-4, -12, -3.5) will move it down and a positive value (2, 7, 5.4) will move it up. Pressing will set C to its default value of 0. Pressing will give C its previous value. If B has not been specified, the brackets will not appear. Are you plotting the graph of y = -0.07( x - 2 )^2 + 9 es or o (Default Yes) If this line displays the correct equation, press or . If it isn't right, press and type it in again. The axis and scales will be drawn, and a message will be printed telling you which equation is being plotted. Change axis With the main menu in front of you, type <2>, for "Change axis". The screen will clear and the following lines will appear one at a time on the 17th line : To move (0,0) horizontally, type -250 to 250 or 0 centre :____ This value effects where the Y axis appears on the screen. A negative number will move it left from the centre, a positive number will move it right from the centre. Pressing will set it to its default value of 0. Pressing will set it to its previous value. Only integers are allowed. To move (0,0) vertically, type -120 to 120 or 0 centre :____ This value effects where the X axis appears on the screen. A negative number will move it down from the centre and a positive number will move it up from the centre. Pressing will set it to its default value of 0. Pressing will set it to its previous value. Only integers are allowed. X - axis scale factor (Default 1) :____ This value effects the number of scale marks on the X axis. A small number (0.5, 0.1) will increase the number of marks, a large number (1.5, 3) will decrease the number of marks. Pressing will set it to its default value of 1. Pressing will set it to its previous value. Negative numbers are not allowed. Y - axis scale factor (Default 1) :____ This value effects the number of scale marks on the Y axis. A small number (0.5, 0.1) will increase the number of marks, a large number (1.5, 3) will decrease the number of marks. Pressing will set it to its default value of 1. Pressing will set it to its previous value. Negative numbers are not allowed. Confirm es or o (Default Yes) This line just asks for confirmation of the settings. If they are wrong, press and go through them again, otherwise press or . A message will appear telling you which equation is being plotted and then the Parabola will be drawn. Change equation and axis Press <3> while in the main menu. This is the same as the previous 2 sections put together. Re-plot graph Press <4> while in the main menu. This will re-plot the last equation. Quit Press while in the main menu. This message will appear : Are you sure (Y or N) If you do wish to exit to the system, press, otherwise press to get back to the main menu. Screen Dumps After the graph has been plotted, a message will appear : Press ~~for screen dump,~~for menu. If you press you will return to the main menu. If you press ~~the current graph will be dumped to a parallel printer. Errors Errors can occur if you type in the wrong thing. After an error has been found, you will be returned to the main menu. Most errors are associated with numbers that are to large. To prevent these errors occuring, try to use small values. Most~~