Topic: how do i use pi?

I´m having trouble with using pi.

I want to plot a function as follows:
f(x) = (pi((2*pi-x)^2/(4*pi^2))(sqrt(1-((2*pi-x)^2)/(4*pi^2)))/3)
...but i only get error message.

When I write:
f(x) = (3.14((2*3.14-x)^2/(4*3.14^2))(sqrt(1-((2*3.14-x)^2)/(4*3.14^2)))/3) works fine.

What could be the problem?

thanks in advance!

Re: how do i use pi?

Did you read the error message?

It tells you that you cannot write a parameter after a constant. This means that pi(2) does not work. Use pi*(2) instead.

Re: how do i use pi?

i agree with the suggestion..pi doesnt usually read ( as a ,multiplication symbol.. instead use * before ()..have you tried it?