C语言怎样表示三角函数计算（注：要用“角度制”表示）

Posted 2023-05-17

1.
C语言的三角函数库采用的单位都是弧度，如果要使用角度，就必须转换，从角度转换成弧度，或者是重写一个三角函数库。
2.
方法一，在调用三角函数之前先把角度换算成弧度，调用反三角函数之后把弧度换算成角度就可以了。可以用
pi
=
4.0
*
atan(1)
算出pi,用
a
=
d
/180.0*pi
转换角度到弧度。
例如：
sin(45
/180.0*pi);
就是计算的sin45。
3.
方法二，直接覆写三角函数。
例如sin函数：
double
dsin(double
d)

return
sin(45
/180.0*pi);
//原理和方法一样，调用的时候直接使用dsin(45)即可
参考技术A 在调用三角函数之前先把角度换算成弧度，调用反三角函数之后把弧度换算成角度就可以了。可以用
pi
=
4.0
*
atan(1)
算出pi,用
a
=
h
*
180.0/pi
算角度，用
h
=
a
*
pi
/180
算弧度。 参考技术B c语言中的三角函数计算需要将角度转弧度，，比如以下代码是计算sin()的值：
#include"stdio.h"
#include"math.h"
#define
pi
3.1415926
main()

int
i;
float
t;
printf("请输入要计算的角度："）;
scanf("%d",i);
t=sin(180*i/pi);
printf（"sin(%d)=%f",i,t);

角度制下的锐角三角函数计算程序

Perl

①

use Win32::Console::ANSI;print "\33[2J\33[H";print "度：";chomp($d=<STDIN>);if($d<=0||$d>=90){print "输入错误：非锐角！\12";}else {print "分：";chomp($_=<STDIN>);$d+=$_/60;if($d<=0||$d>=90){print "输入错误：非锐角！\12";}else {print "秒：";chomp($_=<STDIN>);$d+=$_/60/60;if($d<=0||$d>=90){print "输入错误：非锐角！\12";}else {$r=.31415926535897932384626433832795/18*$d;$x=cos($r);$y=sin($r);print "\33[2J\33[H";print "\33[91msin (";print $d;print "°) = ";print $y;print "\12";print "\33[92msec (";print $d;print "°) = ";print(1/$x);print "\12";print "\33[93mcos (";print $d;print "°) = ";print $x;print "\12";print "\33[94mcsc (";print $d;print "°) = ";print(1/$y);print "\12";print "\33[95mtan (";print $d;print "°) = ";print($y/$x);print "\12";print "\33[96mcot (";print $d;print "°) = ";print($x/$y);print "\12";print "\33[0m";}}}

②

use Win32::Console::ANSI;use Math::Trig;print "\33[2J\33[H", "度：";chomp($d=<STDIN>);if($d<=0||$d>=90){print "输入错误：非锐角！\12";}else {print "分：";chomp($_=<STDIN>);$d+=$_/60;if($d<=0||$d>=90){print "输入错误：非锐角！\12";}else {print "秒：";chomp($_=<STDIN>);$d+=$_/3600;if($d<=0||$d>=90){print "输入错误：非锐角！\12";}else {$r=deg2rad($d);print "\33[2J\33[H", "\33[91msin (", $d, "°) = ", sin($r), "\12", "\33[92msec (", $d, "°) = ", sec($r), "\12", "\33[93mcos (", $d, "°) = ", cos($r), "\12", "\33[94mcsc (", $d, "°) = ", csc($r), "\12", "\33[95mtan (", $d, "°) = ", tan($r), "\12", "\33[96mcot (", $d, "°) = ", cot($r), "\12", "\33[0m";}}}

VB.NET

①

Module Trigonometry Dim d, r, x, y As Primitive Sub Main() TextWindow.Clear() TextWindow.Write("度：") d = TextWindow.ReadNumber() If (d <= 0) Or (d >= 90) Then TextWindow.WriteLine("输入错误：非锐角！") Else TextWindow.Write("分：") d = d + (TextWindow.ReadNumber() / 60) If (d <= 0) Or (d >= 90) Then TextWindow.WriteLine("输入错误：非锐角！") Else TextWindow.Write("秒：") d = d + (TextWindow.ReadNumber() / 60 / 60) If (d <= 0) Or (d >= 90) Then TextWindow.WriteLine("输入错误：非锐角！") Else r = .31415926535897932384626433832795 / 18 * d x = Microsoft.SmallBasic.Library.Math.Cos(r) y = Microsoft.SmallBasic.Library.Math.Sin(r) TextWindow.Clear() TextWindow.ForegroundColor = "Red" TextWindow.WriteLine("sin (" + d + "°) = " + y) TextWindow.ForegroundColor = "Green" TextWindow.WriteLine("sec (" + d + "°) = " + (1 / x)) TextWindow.ForegroundColor = "Yellow" TextWindow.WriteLine("cos (" + d + "°) = " + x) TextWindow.ForegroundColor = "Blue" TextWindow.WriteLine("csc (" + d + "°) = " + (1 / y)) TextWindow.ForegroundColor = "Magenta" TextWindow.WriteLine("tan (" + d + "°) = " + (y / x)) TextWindow.ForegroundColor = "Cyan" TextWindow.WriteLine("cot (" + d + "°) = " + (x / y)) TextWindow.ForegroundColor = "Gray" End If End If End If End SubEnd Module

②

Module Trigonometry Dim d, r, x, y, z As Primitive Sub Main() TextWindow.Clear() TextWindow.Write("度：") d = TextWindow.ReadNumber() If (d <= 0) Or (d >= 90) Then TextWindow.WriteLine("输入错误：非锐角！") Else TextWindow.Write("分：") d = d + (TextWindow.ReadNumber() / 60) If (d <= 0) Or (d >= 90) Then TextWindow.WriteLine("输入错误：非锐角！") Else TextWindow.Write("秒：") d = d + (TextWindow.ReadNumber() / 3600) If (d <= 0) Or (d >= 90) Then TextWindow.WriteLine("输入错误：非锐角！") Else r = Microsoft.SmallBasic.Library.Math.GetRadians(d) x = Microsoft.SmallBasic.Library.Math.Cos(r) y = Microsoft.SmallBasic.Library.Math.Sin(r) z = Microsoft.SmallBasic.Library.Math.Tan(r) TextWindow.Clear() TextWindow.ForegroundColor = "Red" TextWindow.Write("sin (") TextWindow.Write(d) TextWindow.Write("°) = ") TextWindow.WriteLine(y) TextWindow.ForegroundColor = "Green" TextWindow.Write("sec (") TextWindow.Write(d) TextWindow.Write("°) = ") TextWindow.WriteLine(1 / x) TextWindow.ForegroundColor = "Yellow" TextWindow.Write("cos (") TextWindow.Write(d) TextWindow.Write("°) = ") TextWindow.WriteLine(x) TextWindow.ForegroundColor = "Blue" TextWindow.Write("csc (") TextWindow.Write(d) TextWindow.Write("°) = ") TextWindow.WriteLine(1 / y) TextWindow.ForegroundColor = "Magenta" TextWindow.Write("tan (") TextWindow.Write(d) TextWindow.Write("°) = ") TextWindow.WriteLine(z) TextWindow.ForegroundColor = "Cyan" TextWindow.Write("cot (") TextWindow.Write(d) TextWindow.Write("°) = ") TextWindow.WriteLine(1 / z) TextWindow.ForegroundColor = "Gray" End If End If End If End SubEnd Module

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