acosd

计算输入实数的反余弦值对应的角度。

接口定义

C interface：

float acosdf(float x);

double acosd(double x);

long double acosdl(long double x);

参数

参数名

类型

描述

输入/输出

x
  • 在acosdf中，x是单精度浮点类型。
  • 在acosd中，x是双精度浮点类型。
  • 在acosdl中，x是长双精度浮点类型。

表示输入数据的浮点值。

输入

返回值

依赖

C： "km.h"

示例

C interface：

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    // typical usage
    float x1 = -1.0, x2 = 1.0, x3 = 0.5, x4 = -0.5;
    float a = 0.0, b = INFINITY, c = -INFINITY, d = NAN;
    // print result
    printf("acosdf(1.0) = %.15f\n", acosdf(x1));
    printf("acosdf(-1.0) = %.15f\n", acosdf(x2));
    printf("acosdf(0.5) = %.15f\n", acosdf(x3));
    printf("acosdf(-0.5) = %.15f\n", acosdf(x4));
    printf("acosdf(0.0) = %.15f\n", acosdf(a));
    printf("acosdf(-0.0) = %.15f\n", acosdf(-a));
    printf("acosdf(INFINITY) = %.15f\n", acosdf(b));
    printf("acosdf(-INFINITY) = %.15f\n", acosdf(c));
    printf("acosdf(NAN) = %.15f\n", acosdf(d));
    /* 
     * acosdf(1.0) = 180.000000000000000
     * acosdf(-1.0) = 0.000000000000000
     * acosdf(0.5) = 60.000000000000000
     * acosdf(-0.5) = 120.000000000000000
     * acosdf(0.0) = 90.000000000000000
     * acosdf(-0.0) = 90.000000000000000
     * acosdf(INFINITY) = nan
     * acosdf(-INFINITY) = nan
     * acosdf(NAN) = nan
     * 
     * */
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