Prove that sinx + 2x ≥ (3x(x + 1)/π ∀ x ∈ [0, π/2]. (Justify the inequality, if any used).
It is clear that f ′(x) is increasing function in [0, π/2] and there is no local maxima of f(x) in [0, π/2]. The graph of f(x) always **** below
