xt=wherex();yt=wherey(); gotoxy(70,25); textattr(WHITE+(BLACK<<4)); cputs(" "); gotoxy(xt,yt); printf("\n Press any key to exit."); 23 getch(); } /* Dinh nghia ham cho tich phan */ float f(float x,float y) { float H(float,float),a; a=H(x,y)*(float)cos((double)(x*n1))*cos[r]