Question Number 166358 by leicianocosta last updated on 19/Feb/22 | ||
Answered by naka3546 last updated on 19/Feb/22 | ||
$$\frac{\mathrm{3a}^{\mathrm{2}} +\mathrm{5}}{\mathrm{a}^{\mathrm{2}} −\mathrm{1}}\:−\:\frac{\mathrm{3a}^{\mathrm{2}} +\mathrm{1}}{\mathrm{a}^{\mathrm{2}} −\mathrm{1}}\:<\:\mathrm{0} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\frac{\mathrm{4}}{\mathrm{a}^{\mathrm{2}} −\mathrm{1}}\:<\:\mathrm{0} \\ $$$$\mathrm{2}\left(\:\frac{\mathrm{1}}{\mathrm{a}−\mathrm{1}}\:−\:\frac{\mathrm{1}}{\mathrm{a}+\mathrm{1}}\:\right)\:<\:\mathrm{0} \\ $$$$\:\:\:\:\:\:−\mathrm{1}\:<\:\mathrm{a}\:<\:\mathrm{1} \\ $$ | ||