
calculate pi
hi everyone I feel so stupid asking help for these.
i NEED HELP with these part of my code my prompt said :
(computing Π (PI) ) You can approximate (PI) value by using the following
series:
Π = 4( 1 1/3 + 1/5 1/7 + 1/9 1/11 +
 1/(2i 1) + 1/(2i + 1)
Write a method that calculate value of π by using the above series, using
the following header:
public static double pi()
assume i = 1000000
ok so I have been testing it but I really did get any far :
for ( double i = 1; i< 1000000; i+=2) {
// with these I try to increment the value of i to get to the serie.
//I did these after and test it and the output is all wrong and I know it
sum = (1/((2*i)+1));
sum = sum + (1/((2*i)1));
sum ++;
double pi = 4*(sum);
// I know is wrong I but I canīt figure it out what to do.
I am a first semester student of computer science I got the beging of the semester really fast but these is getting harder and my professor is not helping that much..
if someone can help me pleaseee!

Re: calculate pi
Possibly its the maths that you need some help with. The general term in the series you are using is 1/(2 * n  1) where n starts at 1 and continues in increments of 1 until its terminating value  in your case 1000000. So when n = 1, the term is 1/(2 * 1  1) which is 1/1, n = 2 the term is 1/(2 * 2  1) which is 1/3 etc. Every even term is negative so when n is even the term is subtracted from the sum rather than added. The result is then four times the sum.
How a go with this info and post back your code if you still have problems. Please use [code] tags when posting code to make it readable (click go advanced, highlight the code and then click '#'). As it's homwork I can't really give you the code but I'll comment on anything you post back.

Re: calculate pi
thankss
so I got these so far,
but I donīt know how to get the total value of the sum, and also if I should update the variable sum ?
Code:
public class Pi{
public static void main(String[] args)
{
sum =0;
for (int i=3 ; i< 1000000; i+=2){
if (sum%2==0){
sum = 1/(2 * i  1);
}
else {
sum = 1/(2 * i + 1);
}
}

Re: calculate pi
That's not c++. That looks like java or c#? This is the c++ forum.

Re: calculate pi
I know but I couldnīt find out a C# forum can u still give me feedback?

Re: calculate pi
On the main forum page the c# forum is called csharp programming under the header .net programming. You need to scroll down the page until you find it. I really suggest you repost there for c# related questions.
However, the help I can give is this. You loop needs to start at 1 until 1000000 and go up in increments of 1. For every value of the loop you need to calculate the individual term using 1 / (2 * i  1). Then once you have calculated the term, add it to the sum if i is odd or subtract it from the sum if i is even.

Re: calculate pi
thankss! I appreciate the help