In the Laguerre ensemble of N x N (positive) hermitian matrices, it is of
interest both theoretically and for applications to quantum transport problems
to compute the variance of a linear statistic, denoted var_N f, as N->infinity.
Furthermore, this statistic often contains an additional parameter alpha for
which the limit alpha->infinity is most interesting and most difficult to
compute numerically. We derive exact expressions for both lim_{N->infinity}
var_N f and lim_{alpha->infinity}lim_{N->infinity} var_N f.