How to code for summation?

Question

Ashfaq Ahmed 2022-10-5

回答： Walter Roberson 2022-10-5

Hi all,

Can anyone please tell me how can I do the coding to complete this sum?

Also, how can I write down the code that adds up one term after one term and plots them? For example,

x = -pi:0,01:pi;
plot(x,term1); hold on;
plot(x,term1+term2); hold on;
plot(x,term1+term2+term3); hold on;

until all 7 terms! Thank you so much fro your help!!

Answer 1

Walter Roberson 2022-10-5

Your sin(x) term is constant in n, so you can move it outside the summation.

x = -pi:0.01:pi;

sx = sin(x);

factor = cumsum(2./(1:7))

factor = 1×7

2.0000 3.0000 3.6667 4.1667 4.5667 4.9000 5.1857

result = factor .* sx.';

plot(x, result)