Sort out square numbers

(Homework) Create an array of N numbers. Now find a single MATLAB statement that picks out from that array the 1,4,9,16,…,√Nth entries, i.e. those numbers which have indices that are square numbers.

[SL: formatted text as text not code]

[Steven Lord]

Since this is a homework assignment, show us the code you've written to try to solve the problem and ask a specific question about where you're having difficulty and we may be able to provide some guidance.

If you aren't sure where to start because you're not familiar with how to write MATLAB code, I suggest you start with the MATLAB Onramp tutorial (https://www.mathworks.com/support/learn-with-matlab-tutorials.html) to quickly learn the essentials of MATLAB.

If you aren't sure where to start because you're not familiar with the mathematics you'll need to solve the problem, I recommend asking your professor and/or teaching assistant for help.

[Kakande Hannington]

We need serious help on this one as it's not easy

[Walter Roberson]

@Kakande Hannington

Hint:

sqrt(65)

ans = 8.0623

take the 8 part if it

8

ans = 8

square that

8^2

ans = 64

does that equal the original number 65?

What about 121?

sqrt(121)

ans = 11

take the 11 part of it

11

ans = 11

square that

11^2

ans = 121

does that equal the original number 121?

By using this logic, if you had the index of a value in a vector, you could detect whether the index is the square of an integer. Comparisons ("does that equal") can return a logical vector, which you can then use to index the original array.

(Not saying this is the easiest way!)