Question Number 13812 by Tinkutara last updated on 23/May/17
$$\mathrm{The}\:\mathrm{domain}\:\mathrm{of}\:{f}\left({x}\right)\:= \\ $$$$\sqrt{\left(\frac{\mathrm{4}}{\mathrm{3}}\right)^{\mathrm{4}−{x}} −\left(\frac{\mathrm{27}}{\mathrm{64}}\right)^{{x}−\mathrm{5}} };\:\mathrm{is}? \\ $$
Answered by ajfour last updated on 23/May/17
$$\left(\frac{\mathrm{4}}{\mathrm{3}}\right)^{\mathrm{4}−{x}} \geqslant\left(\frac{\mathrm{4}}{\mathrm{3}}\right)^{\mathrm{15}−\mathrm{3}{x}} \\ $$$$\Rightarrow\:\:\mathrm{4}−{x}\geqslant\mathrm{15}−\mathrm{3}{x} \\ $$$${or},\:\:\:\:{x}\geqslant\frac{\mathrm{11}}{\mathrm{2}}\:. \\ $$
Commented by Tinkutara last updated on 23/May/17
$$\mathrm{Thanks}! \\ $$