HP 33s hp 33s_user's manual_English_E_HDPM20PIE56.pdf - Page 68

Setting the Angular Mode The angular mode specifies which unit of measure to assume for angles used in trigonometric functions. The mode does not convert numbers already present (see "Conversion Functions" later in this chapter). 360 degrees = 2π radians = 400 grads To set an angular mode, press Ÿ. A menu will be displayed from which you can select an option. Option Description Annunciator {} {} {} Sets Degrees mode (DEG). Uses decimal degrees, not degrees, minutes, and seconds. Sets Radians mode (RAD). Sets Grads mode (GRAD). none RAD GRAD Trigonometric Functions With x in the display: To Calculate: Press: Sine of x. O  Note Cosine of x. Tangent of x. Arc sine of x. Arc cosine of x. Arc tangent of x. R U {M {P {S Calculations with the irrational number π cannot be expressed exactly by the 12-digit internal precision of the calculator. This is particularly noticeable in trigonometry. For example, the calculated sin π (radians) is not zero but -2.0676 × 10-13, a very small number close to zero. 4-4 Real-Number Functions