C 数学函数

  #include <stdio.h> 
  #include <stdlib.h> 

  #include <math.h> 

  int main() { 
     float a; 
     float b; 
     float pi = 3.14; 

     a = 0.5; 
     printf("value a = % .2f \n",a); 

     b = abs(-a); 
     printf("abs(a)=% .2f \n",b); 

     b = acos(a); 
     printf("acos(a)=% .2f \n",b); 

     b = asin(a); 
     printf("asin(a)=% .2f \n",b); 

     b = atan(a); 
     printf("abs(a)=% .2f \n",b); 

     b = atan2(a,5); 
     printf("atan(a,5)=% .2f \n",b); 

     b = cos(a); 
     printf("cos(a)=% .2f \n",b); 

     b = sin(a); 
     printf("sin(a)=% .2f \n",b); 

     b = tan(a); 
     printf("tan(a)=% .2f \n",b); 

     b = sqrt(a); 
     printf("sqrt(a)=% .2f \n",b); 

     return 0; 
  }