Performing Special Functions Calculator performs special functions including trigonometric and inverse trigonometric functions. The special functions keys are as follows: Key Description deg Degree key. Selects the units for angular measurement. By default, Calculator is in the degree mode. Clicking on the deg key once places Calculator in the radian mode, which is indicated by the key label changing to "rad." Clicking on the key again places Calculator in gradian mode, which is indicated by the key label changing to "grad." The angular mode has no effect on Calculator unless the trigonometric functions are being used. x! Factorial key. Calculates the facto(~)(~ ~1)(~ ~2)~~(1) of the value x in the display for integers. 1/x Reciprocal key. Divides the displayed value x into 1. for x!=0. Rnd Random number generator key. Generates a random number between 1 and the integer of the display. It does not generate negative numbers or numbers less than 1. Inv Inversion key. By default, Calculator performs noninverted trigonometric functions. When you activate the inversion key by clicking on it (which is indicated by the key becoming darkened), Calculator performs inverted trigonometric functions. sin Sine key. Instructs Calculator to find the sine of the dis- played value. cos Cosine key. Instructs Calculator to find the cosine of the displayed value. tan Instructs Calculator to find the tangent of the displayed value. log Common logarithm key. Calculates the common logarithm (base 10) of the number x in the display for x > 0. ln Natural logarithm key. Calculates the natural logarithm (base e) of the number x in the display for x > 0. square Square root key. Calculates the square root of the number x root in the display. The x value cannot be negative. y^x y to the xth power key. Raises the displayed value y to the xth power. Order of entry is y, y^x key, x. The y value cannot be negative, but both x and y can be fractional. and Logical and. or Logical or. xor Logical xor. nor Logical nor. not Logical not. neg Logical neg. Additional topics: * Performing Arithmetic Functions * Calculating Square Roots * Calculating Percentages * Clearing the Displays * Using Memory * Undoing the Most Recently Performed Function * Exiting Calculator * Using Calculator's Menus * Keyboard Special Function Keys * Keyboard Memory Function Keys * Overview of Calculator