# how to create a matrix with variables in it?

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siva senthil on 12 Feb 2013
Commented: Walter Roberson on 25 Apr 2021
for eg., to create following matrix and work on it,
A=[x1 x1*x2 ; x1^2 x2^2]

Kye Taylor on 12 Feb 2013
Edited: Kye Taylor on 12 Feb 2013
The best answer to your question will likely depend on what you want to do with A. Sometimes, I find the following commands useful, which will create an anonymous function, A, that takes two inputs, x1 and x2 and returns the matrix you describe. Of course, this assumes you have values for the variables x1 and x2.
A = @(x1,x2)[x1,x1*x2;x1^2,x2^2]
And compute, for example, with
det(A(1,2))
If you want A to be symbolic, you can begin using the following command
syms x1 x2
A = [x1,x1*x2;x1^2,x2^2]
Then compute, for example, with
det(A)

Aman Kumar on 23 Mar 2021
syms x1 x2
A = [x1,x1*x2;x1^2,x2^2]
Michael Wolfe on 25 Apr 2021
How would you make a matrix with both numbers and variables in it?
Walter Roberson on 25 Apr 2021
syms x1 x2
A = [x1,x1*pi;.8,x2^2]