HP 39GS HP 39gs_40gs_Mastering The Graphing Calculator_English_E_F2224-90010.p - Page 37

The HOME History The HOME page maintains a record of all your calculations called the History. You can re-use any of the calculations or their results in subsequent calculations. Try this for yourself now. Type in at least four calculations of any kind, pressing the ENTER key after each one to tell the calculator to perform the calculation. You will now be looking at a screen similar to the one on the right (except probably with different calculations). If you now press the up arrow key, a highlighted bar moves up the screen. When you reach the top of the screen the previous calculations will scroll into view. Pressing SHIFT up-arrow takes the highlight to the top in one movement. COPYing calculations You may have noticed that as soon as the highlight appeared so did two labels at the bottom of the screen. If you now press the screen key under you will find that the highlighted calculation will be copied on the edit line. This is shown in the screen shot on the right. At this point you can use the left and right arrows and the DEL key to edit the calculation by removing some of the characters and/or adding to it. For example, in the screenshot right, the calculation of 3*2*COS(35) has been edited to 3*COS(35). Clearing the History Pressing enter will now cause this new calculation to be performed. Calculator Tip Pressing ON during editing will erase the whole line. Pressing SHIFT CLEAR erases the whole history. This is worth doing regularly, since the history uses memory that may be needed for other things, even with the immense amount of user memory the hp 39gs & hp 40gs have. You can calculations and results from any number of different lines in building your new expression. 37