Previous in Relation and Functions Next in Relation and Functions
Question Number 32284 by abdo imad last updated on 22/Mar/18
![prove that ∀ x∈[0,(π/4)] x≤tanx≤2x 2) find α_n and β_n from R / α_n ≤ Σ_(k=2) ^n tan((π/(2n)))≤ β_n](Q32284.png)
$${prove}\:{that}\:\forall\:{x}\in\left[\mathrm{0},\frac{\pi}{\mathrm{4}}\right]\:\:{x}\leqslant{tanx}\leqslant\mathrm{2}{x} \\ $$$$\left.\mathrm{2}\right)\:{find}\:\alpha_{{n}} \:{and}\:\beta_{{n}} \:{from}\:{R}\:/\:\:\alpha_{{n}} \leqslant\:\sum_{{k}=\mathrm{2}} ^{{n}} \:{tan}\left(\frac{\pi}{\mathrm{2}{n}}\right)\leqslant\:\beta_{{n}} \\ $$