Sum of a Series, Help!

Hi i have had a look around for some help on multiple variables using sum and sigma.

Couldnt quite understand how to apply those examples to my problem.

And I have got to write out this function and be able to plot it on a graph.

Being that n is 1,2 or 3 (on the same graph)

Pn(x) =

[Nathan Barnes]

I do apologise if I broke ToS here, I would just like to remove the thread if that is ok?

[madhan ravi]

Why?

[Stephen23]

Original question by Nathan Barnes retrieved from Google Cache:

"Sum of a Series, Help!"

Hi i have had a look around for some help on multiple variables using sum and sigma.

Couldnt quite understand how to apply those examples to my problem.

And I have got to write out this function and be able to plot it on a graph.

Being that n is 1,2 or 3 (on the same graph)

[madhan ravi]

Thank you Stephen!

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[David Hill]

Not sure exactly what you are asking.

x=0:.1:10;
for n=1:3
    S(n,:)=arrayfun(@(i)sum(repmat(-1,1,n+1).^(0:n)./(2*(0:n)+1).*repmat(i,1,n+1).^(2*(0:n)+1)),x);
end
subplot(3,1,1);
plot(x,S(1,:));

subplot(3,1,2); 
plot(x,S(2,:));

subplot(3,1,3); 
plot(x,S(3,:));

[madhan ravi]

See after providing a complete solution usually the OP deletes the question. That’s why it’s better to provide hints than a complete solution.

[Nathan Barnes]

It is correct and I appreciate it very much, I'm sorry if I came off as ungreatful.

[Rik]

Then why did you delete it?

Answer 2

[Boxn Hen]

Hope to help you as follow.Ps:I just use 'for' to sum all seperate results.

function result=SumAndSigma(x,n)
r(1)=0;
for i=0:n
    r(i+2)=r(i+1)+((-1)^i/(2*i+1)).*x.^(2*i+1)% There are n+1 elements and the first one is 0.
end
result=r(2:end);
end

And input x and n to the function SumAndSIgma.

 %for example:x=3;n=5
x=3;n=5;
result=SumAndSigma(x,n)
data=0:n;
plot(data,result);