HP 39g hp 39g+ (39g & 40g)_mastering the hp 39g+_English_E_F2224-90010.pdf - Page 17

KEYS & NOTATION CONVENTIONS There are a number of types of keys/buttons that are used on the hp 39g+. Some essential keys The basic keys are those that you see on any calculator including scientific ones, such as the numeric operators and the trig keys. Most of these keys have two or more functions. Take for example the COS key shown left. If you just press the key, you get the COS function. However above left of the key and below right you will see two additional meanings assigned via the SHIFT and ALPHA keys. All references to keys, whether they need the SHIFT key or not, are written in this typeface: KEY. The SHIFT key The SHIFT key gives you the second function for each key. In the case of the COS key, the second function is ACOS, sometimes referred to as arc-cos or cos-1 or inverse cos. Most keys have these second functions that are obtained via the SHIFT key. When I want you to use one of these keys that needs to have the SHIFT key pressed first I usually won't say so. It seems to me that you're intelligent enough to work out for yourself when the SHIFT key needs to be pressed. 17