C/C++の宿題を片付けます 65代目

>>971
#include<stdio.h>
#include<stdlib.h>
#include<math.h>
int main(int argc,char* argv){char tmp[100];double dx,s,y,t=0.0,x=0.0;FILE* fp;
if(argc>1){if((fp=fopen(argv[1],"r"))){while(fgets(tmp,sizeof(tmp),fp)!=EOF){
dx=atof(tmp);y=sin(x);s=y*2*dx;x+=dx;printf("dx=%fの時面積%f\n",dx,s);t+=s;}fclose(fp);}
printf("円の面積:%f\n",t);return 0;}