uTools-Manuals/docs/c/atan2.html

<h1>数学函数 - atan2</h1>


  <p>原型：extern float atan2(float y, float x);</p>
  
  <p>用法：#include &lt;math.h></p>
  
  <p>功能：求y/x（弧度表示）的反正切值</p>
  
  <p>说明：值域为(-π/2，+π/2)。</p>
  
  举例：<pre>

      // atan2.c
      
      #include &lt;syslib.h>
      #include &lt;math.h>

      main()
      {
        float x,y;
        
        clrscr();        // clear screen
        textmode(0x00);  // 6 lines per LCD screen
        
        x=0.064;
        y=0.2;
        printf("atan2(%.3f,%.2f)=%.4f",y,x,atan2(y,x));
        
        getchar();
        return 0;
      }
      
  </pre>相关函数：<a href="asin.html">asin</a>,<a href="acos.html">acos</a>,<a href="atan.html">atan</a>,<a href="sin.html">sin</a>,<a href="cos.html">cos</a>,<a href="tan.html">tan</a>