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how do I right x^2 in MATLAB

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i trying to do some equetion and i come up with an erro message every time i right it out

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Accepted Answer

John D'Errico
John D'Errico on 23 Nov 2020
Edited: John D'Errico on 23 Nov 2020
Is x a scalar? If so, then you write it as x^2.
Is x a vector? Then, assuming you want to perform an element-wise squaring, you use x.^2.
If you are asking this question, you REALLY need to be reading the getting started tutorials - the Onramp tutorials are a good place to start. There are also multiple MATLAB tutoring sessions on Youtube to watch.
Finally, when you get an error. then show what you did. Show the COMPLETE error message, thus everything in red. Otherwise we need to make wild guesses as to what you did wrong.

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John D'Errico
John D'Errico on 24 Nov 2020
Honestly, I think you are giving up, not trying. It is just too overwhelming for you, so you give up before you ever start. Then you just ask someone to write the code for your assignments. You won't learn that way. So try this:
Given two vectors, x and y, can you multiply the elements of the two vectors?
x = [1 2 3 4];
y = [2 3 5 7];
The result (element-wise product) should be
z = [2 6 15 28]
What one line of code would have you multiply the vectors x and y? I've already told you how to do it. So try it. Show me that you want to learn. And then we can take the next step, building up what you need to do to get a solution.
Steven Lord
Steven Lord on 24 Nov 2020
John and Rik both suggested that you work through the MATLAB Onramp tutorial and I agree with that suggestion. It is about a two hour long free course with videos and hands-on exercises that are automatically scored (so you get feedback about whether your answer is correct right away) and is designed to teach you the basics of working with MATLAB. I suspect after taking sections 4 and 6 you will understand the difference between the ^ and .^ operators and be able to answer your question.

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More Answers (1)

Steven Lord
Steven Lord on 23 Nov 2020
To raise a square matrix to a power use the ^ operator.
To raise each element of an array (the array need not be square or even 2-dimensional) to a power use the .^ operator.
A = [1 2; 3 4]
A = 2×2
1 2 3 4
S1 = A^2
S1 = 2×2
7 10 15 22
S2 = A.^2
S2 = 2×2
1 4 9 16
If your matrix is not square (for example, if it is a row vector) then .^ will work but ^ will not.
thisWillWork = (1:5).^2
thisWillWork = 1×5
1 4 9 16 25
thisWillNOTWork = (1:5)^2
Error using ^ (line 51)
Incorrect dimensions for raising a matrix to a power. Check that the matrix is square and the power is a scalar. To perform elementwise matrix powers, use '.^'.

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Steven Lord
Steven Lord on 23 Nov 2020
If you're asking if you can email me directly, I'm on vacation for the next week or so (only sporadically checking Answers.) Posting your follow-up questions as comments on this post (or as new posts, if they're unrelated to this topic) will let others answer more quickly than I will.
Alex Walton
Alex Walton on 23 Nov 2020
you seam more helpfull... my e male is alex-walton3@sky.com
Image Analyst
Image Analyst on 24 Nov 2020
Alex, why won't you ask questions here so all of can benefit from the discussion (like Steven specifically said)? Most volunteers here don't like offering free, private consulting via email when the Mathworks went to all this trouble to set up this nice forum for everyone's benefit. Besides, other people are helpful too. We volunteers range anywhere from people who simply give you the answer outright, to those like John who try to guide you to the answer so that you learn it more deeply than just being handed an answer. Even though John and Steve's approach may not be the fastest today, if you learn MATLAB, you will be faster in the future and won't have to ask. Indeed, hopefully you'll be the expert one day and be helping others here.

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