Matlab - Incorrect dimensions for raising a matrix to a power

[poster]

Suppose we have a=60 and B=60. I am trying to calculate this area:

when I try this:

W = ((u^2)* cot(B) + (v^2 * cot(a))/8;

I get this error:

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 '.^'.

How can I use u^2 in the right way?

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