You will need to use the element-wise or array versions of the division and power operators. See this documentation page for an explanation of the different between the element-wise / array operators and the matrix operators.
As a simple example of the difference, using the times array operator ".*" and the mtimes matrix operator "*":
A = [1 2 3; 4 5 6; 7 8 9]
B = [1 4 7; 2 5 8; 3 6 9]
elementwise = A.*B
matrix = A*B
