Basic PHP - help with course work?

I'm currently learning PHP on a short course and have this task...

The script should write the following: "3.14155265", without using the digits displayed, as simply as possible, using only Integers and Strings..

If you can help and explain, thanks in advance.

Anwered 2010-03-03 20:18:36 by Robin T

That's the value of 'pi'. Just use the function pi().
e.g.: echo pi();

And because you want it to output only 8 numbers after the decimal point, you can use number_format() function.
e.g.: echo number_format( pi(), 8 );

For more info look at:
http://php.net/pi
http://php.net/number_format

Anwered 2010-03-03 21:42:24 by Chris C

Here is the algorithm:
define numbers a,b,c such that at the initial state:
a=x=1
b=1/sqrt(2)
c=1/4

then iterate:
y=a
a=(a+b)/2
b=sqrt(b*y)
c=c-x(a-y)*(a-y)
x=2x

such that pi=(a+b)*(a+b)/4c