Do you mean you want the reciprocal of each element of each matrix? (That is not what the inverse of a matrix means.)
If so, then you want
x1 = rand(10,10);
y1 = rand(10,10);
z1 = rand(10,10);
r1 = rand(10,10);
a1 = cat(3,x1,y1,z1,r1);
x2 = rand(10,10);
y2 = rand(10,10);
z2 = rand(10,10);
r2 = rand(10,10);
a2 = cat(4,x2,y2,z2,r2);
tmp = num2cell(sqrt(a1./a2),3:4);
fun = @(a)reshape(a,4,4);
out = cellfun(fun,tmp,'uni',0);
out2=cellfun(@(x) 1./x, out, 'uniform', 0);
% example of one reciprocal:
out{1}
out2{1}