Every C# application .EXE file must contain an entry point - it's where the application begins executing when you try to run it. Without that entry point, it's not a EXE file (though it can still be an Assembly, but don't worry about that for the moment - you'll get to it later)
The entry point you need it a method called
Main
which can call your new function. Oh, and by the way - your homework calls for two parameters, not three!
using System;
namespace GeneralTestingConsole
{
class Program
{
public static void Main()
{
ComputeSalesTax(100.0, 10.0);
ComputeSalesTax(100.0, 17.5);
}
static void ComputeSalesTax(double saleAmount, double taxRate)
{
double tax = taxRate * saleAmount;
Console.WriteLine("The tax on {0} at {1} is {2}",
saleAmount.ToString("C"),
taxRate.ToString("P"), tax.ToString("F"));
}
}
}