In [1]:
are <- function(eps, sc2) {
    "Return asymptotic relative efficiency of a contaminated normal distribution"
    return(2 * (1+eps*(sc2-1)) * (1 - eps + eps/sqrt(sc2))^2 / pi)
}

In [2]:
eps <- seq(0, 0.15, by=0.05)
round(are(eps, 9), 3)


Out[2]:
  1. 0.637
  2. 0.833
  3. 0.998
  4. 1.134

In [3]:
are_min_1 <- function(eps, sc2) {
    return (are(eps, sc2) - 1)
}

In [4]:
uniroot(are_min_1, sc2=9, interval=c(0.1, 0.15))$root


Out[4]:
0.10059207725643