Remote Processing BASIC 52 - Manual (Page 130)

RPBASIC-52 PROGRAMMING GUIDE
2-111
TAN
Syntax: T A N (expr)
Function: Returns the trigo nometric tan gent (sin/cos) of expr whic h is assu med to be in radian s. expr must be
in the range of +/- 200,000.
Mode: Comm and, run
Use: PRINT TA N(PI/4)
Cards: All
D E S C R IP T I ON
SIN, COS, and TAN operators use a Taylor series to calculate the function. These operators first reduce the
argument to a value that is between 0 and PI/2. the algorithm used to reduce the value will reduce accuracy
when value is large. To maintain accuracy, keep the arguments for trig functions as small as possible.
ERRORS
A R I T H . U N D E R F L O W value or result is less than RPBASIC-52's smallest floating-point value of ± 1E-127
A R I T H . O V E R F L O W value or result is greater than RPBASIC-52's largest floating-point value of
±.9999999E+127
D I V I DE B Y Z E R O Attempt to take TAN(X) when COS(PI/2) = 0
EXAMPLES
100 PRINT SIN(PI/2),COS(10001*PI),TAN(5*PI/4)
110 PRINT ATN(TAN(PI/4))/PI
>run
1 -1 1
.24999996