HP 39gs User Manual page 157

ATAN
ABS
Using mathematical functions
–1
Arc tangent: tan
2π/2 to π/2, or –100 to 100 grads. Inputs and outputs
depend on the current angle format. Also accepts
complex numbers.
ATAN(value)
Example
ATAN(1) returns 45 (Degrees mode).
Square. Also accepts complex numbers.
2
value
Example
2
18 returns 324
Square root. Also accepts complex numbers.
value
Example
324
returns 18
Negation. Also accepts complex numbers.
–value
Example
-(1,2) returns (-1,-2)
Power (x raised to y). Also accepts complex numbers.
value^power
Example
2^8 returns 256
Absolute value. For a complex number, this is
ABS(value)
ABS((x,y))
Example
ABS(–1) returns 1
ABS((1,2)) returns 2.2360679775
x. Output range is from –90° to 90°,
2 2
x + y
.
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