Question

Using binomial approxination
[
begin{array}{l}
=xleft(1+frac{1}{3}left(frac{(a+b+c)(a b+b c+c a+a b c)}{x^{2}}right)-xright.
=lim _{n rightarrow infty}left(frac{1}{3}(a+b+c)+a b+b c+c a+a b cright)
=frac{a+b+c}{3}
end{array}
]

# Lustration : Lim ((x+a)(x+b)(x+c)}/3 - x

Solution