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Q-solve-2-sin-2-x-sin-2-x-3-cos-2-x-cos-2-x-6-




Question Number 78358 by aliesam last updated on 16/Jan/20
Q. solve    (2^(sin^2 (x)) /(sin^2 (x) )) + (3^(cos^2 (x)) /(cos^2 (x))) = 6
$${Q}.\:{solve} \\ $$$$ \\ $$$$\frac{\mathrm{2}^{{sin}^{\mathrm{2}} \left({x}\right)} }{{sin}^{\mathrm{2}} \left({x}\right)\:}\:+\:\frac{\mathrm{3}^{{cos}^{\mathrm{2}} \left({x}\right)} }{{cos}^{\mathrm{2}} \left({x}\right)}\:=\:\mathrm{6} \\ $$
Commented by MJS last updated on 16/Jan/20
the minimum of the lhs is 2((√3)+(√2))>6 at  x=(π/4)+(π/2)n ⇒ no solution ∈R
$$\mathrm{the}\:\mathrm{minimum}\:\mathrm{of}\:\mathrm{the}\:\mathrm{lhs}\:\mathrm{is}\:\mathrm{2}\left(\sqrt{\mathrm{3}}+\sqrt{\mathrm{2}}\right)>\mathrm{6}\:\mathrm{at} \\ $$$${x}=\frac{\pi}{\mathrm{4}}+\frac{\pi}{\mathrm{2}}{n}\:\Rightarrow\:\mathrm{no}\:\mathrm{solution}\:\in\mathbb{R} \\ $$

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