void quadratic_equation(void)
{
float a,b,c,root1,root2,d,vr1,vr2;
printf("Enter a,b,c:");
scanf("%f %f %f",&a,&b,&c);
if(!a)
{
if(!b)
{
if(!c)
printf("any root");
else
printf("no root!");
}
printf("only one root root = %f",-c/b);
}
else
{
d=b*b-4*a*c;
if(d>=0)
{
root1 = (-b+sqrt(d))/2*a;
root2 = (-b-sqrt(d))/2*a;
printf("root1 = %f, root2 = %f",root1,root2);
}
else
{
vr1=-b/2*a;
vr2=sqrt(-d)/2*a;
printf("root1 =%6.2f +%6.2fi\n",vr1,vr2);
printf("root2 =%6.2f -%6.2fi",vr1,vr2);
}
}
}
2.Personal_Tax_Calcuator
void P_Tax(void)
{
float dSalary,dTax=0,dNetIncome=0,dRate = 0;
printf("Enter your salary: ");
scanf("%f", &dSalary);
float a=dSalary-3500;
if(a<0)
dRate = 0, dNetIncome = 0;
else if(a<1500)
dRate = 0.03, dNetIncome = 0;
else if(a<4500)
dRate = 0.10, dNetIncome = 105;
else if(a<9000)
dRate = 0.20, dNetIncome = 555;
else if(a<35000)
dRate = 0.25, dNetIncome = 1005;
else if(a<55000)
dRate = 0.30, dNetIncome = 2755;
else if(a<80000)
dRate = 0.35, dNetIncome = 5505;
else
dRate = 45, dNetIncome = 13505;
dTax = a*dRate - dNetIncome;
printf("your tax is %.2f , \nafter tax income is %.2f.\n", dTax, dSalary-dTax);
printf("Thanks for your using!\n");
}
void tri_angle(void)
{
float x,y;
int flag=1;
scanf("%f",&x);
if(x>=0)
y=(sin(x/180*pi)+flag*cos(x/180*pi))/2;
else
{
flag=!flag;
y=(sin(x/180*pi)+flag*cos(x/180*pi))/2;
}
printf("y is %f",y);
}