Let ƒ : R $ \to $ R be such that for all x $ \in $ R (21+x + 21–x), ƒ(x) and (3x + 3–x) are in A.P., then the minimum value of ƒ(x) is

Question

Let ƒ : R $ \to $ R be such that for all x $ \in $ R
(2^1+x + 2^1–x), ƒ(x) and (3^x + 3^–x) are in A.P.,
then the minimum value of ƒ(x) is

Please login to view the detailed solution steps...