asinpi
Compute the arcsine of the input real number and divide the arcsine by π.
Interface Definition
C interface:
float asinpif(float x);
double asinpi(double x);
Parameters
Parameter |
Type |
Description |
Input/Output |
|---|---|---|---|
x |
For asinpif, x is of single-precision floating-point type. For asinpi, x is of double-precision floating-point type. |
Floating-point value of a sine value. |
Input |
Return Value
- The result y is returned following the formula y = asin(x)/π. y ∈ [-0.5, +0.5]
- If the input is +0, the return value is +0.
- If the input is -0, the return value is -0.
- If the input x is ±1, the return value is ±0.5.
- If the input |x| is greater than 1, the return value is NaN.
- If the input is ±∞, the return value is NaN.
- If the input is NaN, the return value is NaN.
Dependency
C: "km.h"
Example
C interface:
// print result
printf("asinpi(0.0) = %.15f\n", asinpi(0.0));
printf("asinpi(-0.0) = %.15f\n", asinpi(-0.0));
printf("asinpi(0.25) = %.15f\n", asinpi(0.25));
printf("asinpi(-0.25) = %.15f\n", asinpi(-0.25));
printf("asinpi(0.5) = %.15f\n", asinpi(0.5));
printf("asinpi(-0.5) = %.15f\n", asinpi(-0.5));
printf("asinpi(1.0) = %.15f\n", asinpi(1.0));
printf("asinpi(-1.0) = %.15f\n", asinpi(-1.0));
printf("asinpi(INFINITY) = %.15f\n", asinpi(INFINITY));
printf("asinpi(-INFINITY) = %.15f\n", asinpi(-INFINITY));
printf("asinpi(NAN) = %.15f\n", asinpi(NAN));
printf("asinpi(-NAN) = %.15f\n", asinpi(-NAN));
/*
* asinpi(0.0) = 0.000000000000000
* asinpi(-0.0) = -0.000000000000000
* asinpi(0.25) = 0.080430623255166
* asinpi(-0.25) = -0.080430623255166
* asinpi(0.5) = 0.166666666666667
* asinpi(-0.5) = -0.166666666666667
* asinpi(1.0) = 0.500000000000000
* asinpi(-1.0) = -0.500000000000000
* asinpi(INFINITY) = nan
* asinpi(-INFINITY) = nan
* asinpi(NAN) = nan
* asinpi(-NAN) = -nan
*
* */
Parent topic: Trigonometric Functions