  We evaluate the maximum value of the unique positive solution to semilinear
elliptic equations with double power nonlinearities. It is known that a
positive solution to this problem exists under some condition.Moreover, Ouyang
and Shi in 1998 found that the solution is unique under the same condition. In
the present paper we investigate the maximum value of the solution. The key
idea is to examine the function defined from the nonlinearity, which arises
from the well-known Pohozaev identity.
