how to do this array problem matlab

 z=[2j;-pi/2;3]

https://www.dropbox.com/s/kdttn8irinpf8xr/Screenshot%202015-03-21%2023.06.02.png?dl=0

 sqrt(zk) where zk is the kth element of array z.

[Geoff Hayes]

HIGH - please describe in detail what problem you are attempting to solve. Instead of posting a link to an image, describe it in worlds.

[HIGH]

we have to specify the Matlab command that we would enter in order to evaluate the indicated sigma quantity . I cannot type it the symbols. that is why I posted the link to the question. Sorry I am new to this forum.

Answer 1

[Naty S]

Hey HIGH If I understand you correctly you want to sum the square value of a vector. Check the functions sum and sqrt http://www.mathworks.com/help/matlab/ref/sum.html?searchHighlight=sum http://www.mathworks.com/help/matlab/ref/sqrt.html?searchHighlight=sqrt

d=sum(sqrt(z(k:3)))

[HIGH]

 is this right too?

d=sum(sqrt(z(1:3)))

because when I did it your way it asks me to define k. so I typed k=(1:3).. then it gave me 2.7321 + 2.2533i... also when I did d=sum(sqrt(z(1:3))), it gave me the same answer. both ways are correct it seems?