Plot series in Matlab

Question

I am new in Matlab and I am trying to plot this function in Matlab:

I am using the following code:

t = -2*pi:0.01:2*pi;
f = sum(cos(2*pi*i*t), i = 1 .. 10);
plot(t, f)

But I getting this message error:

f = sum(cos(2*pi*i*t), i = 1 .. 10);
                            |
Error: The expression to the left of the equals sign is not a valid target for an assignment.

Can anyone help me?

EDIT: I am using Matlab 2013a

Answer 1

 t = -2 * pi : 4 * pi / 500 : 2 * pi;
 f = sum(cos(2 * pi * (1 : 10)' * t), 1);
 plot(t, f);

• doc sum, of course ))