Unrecognized function or variable 'x'.

Here is the code that i worte:

% Let's solve the nonlinear system below using successive 
% substitution
%x^2=5-y^2
%Y+1=x^2

%Guess
x1=1.5;
x2=1.5;

% Successive Substitution 
for i=1:10
y1=x.^2-1;
y2=sqrt(5-x.^2);
end

I keep getting the error Unrecognized function or variable 'x'. Can someone explain what I am missing?

Answer 1

[John D'Errico]

Where exactly did you define the value of x?

I see this line:

%x^2=5-y^2

But there is the minor flaw of a comment. Anyway, that does not define a variable named x. You cannot hve x^2 on the left side of an assignment.

Now, read the error message:

Unrecognized function or variable 'x'.

So, I'll ask again, where did you define x? (You did not.)

[Anonymous]

I am not very sure how to do that. This is all the code my teacher gave me to run but i keep getting the code

[John D'Errico]

If you do not know how to do something as simple as assign some value to a variable named x, then it would seem you need to start at the beginning. Read the getting started tutorials. Sorry, but it is time to at least read the very beginning of the manual. Even the very first page will tell you as much as you need. But if you do not spend the time to learn what you are doing, then you will be asking constant questions like this, to please teach you the very most basic ideas.

Fir some reason, it seems like you have figured out how to assign values to the variables x1 and x2. (Hint.) But then you never used them.

Seriously, you need to read the manual.

Answer 2

[Jianling Zhao]

Unrecognized function or variable 'oaxes'.

[Walter Roberson]

https://www.mathworks.com/matlabcentral/fileexchange/30018-oaxes-central-axis-lines-through-an-origin

[Jianling Zhao]

>> b(1:5) = Account

The following error occurred converting from Account to double:

Conversion to double from Account is not possible.

[Walter Roberson]

I have no idea what datatype Account is in your code. What shows up for

whos Account