Question Number 133996 by mr W last updated on 26/Feb/21
![show that (√2)<log_2 3<(√3)](https://www.tinkutara.com/question/Q133996.png)
$${show}\:{that}\:\sqrt{\mathrm{2}}<\mathrm{log}_{\mathrm{2}} \:\mathrm{3}<\sqrt{\mathrm{3}} \\ $$
Answered by som(math1967) last updated on 26/Feb/21
![2^(√2) <3<2^(√3) log_2 2^(√2) <log_2 3<log_2 2^(√3) (√2)<log_2 3<(√3)](https://www.tinkutara.com/question/Q134017.png)
$$\:\:\mathrm{2}^{\sqrt{\mathrm{2}}} <\mathrm{3}<\mathrm{2}^{\sqrt{\mathrm{3}}} \\ $$$${log}_{\mathrm{2}} \mathrm{2}^{\sqrt{\mathrm{2}}} <{log}_{\mathrm{2}} \mathrm{3}<{log}_{\mathrm{2}} \mathrm{2}^{\sqrt{\mathrm{3}}} \\ $$$$\sqrt{\mathrm{2}}<{log}_{\mathrm{2}} \mathrm{3}<\sqrt{\mathrm{3}} \\ $$
Commented by som(math1967) last updated on 26/Feb/21
![Is my way correct sir?](https://www.tinkutara.com/question/Q134018.png)
$${Is}\:{my}\:{way}\:{correct}\:{sir}? \\ $$
Commented by mr W last updated on 26/Feb/21
![we may not use calculator. how is it obviour that 2^(√2) <3<2^(√3) ?](https://www.tinkutara.com/question/Q134021.png)
$${we}\:{may}\:{not}\:{use}\:{calculator}.\:{how}\:{is}\:{it} \\ $$$${obviour}\:{that}\:\mathrm{2}^{\sqrt{\mathrm{2}}} <\mathrm{3}<\mathrm{2}^{\sqrt{\mathrm{3}}} \:? \\ $$
Answered by mr W last updated on 26/Feb/21
![9>8 3^2 >2^3 2 log_2 3>3 log_2 3>(3/2) (log_2 3)^2 >((3/2))^2 =(9/4)>(8/4)=2 ⇒log_2 3>(√2) 27<32 3^3 <2^5 3log_2 3<5 log_2 3<(5/3) (log_2 3)^2 <((5/3))^2 =((25)/9)<((27)/9)=3 ⇒log_2 3<(√3)](https://www.tinkutara.com/question/Q134033.png)
$$\mathrm{9}>\mathrm{8} \\ $$$$\mathrm{3}^{\mathrm{2}} >\mathrm{2}^{\mathrm{3}} \\ $$$$\mathrm{2}\:\mathrm{log}_{\mathrm{2}} \:\mathrm{3}>\mathrm{3} \\ $$$$\mathrm{log}_{\mathrm{2}} \:\mathrm{3}>\frac{\mathrm{3}}{\mathrm{2}} \\ $$$$\left(\mathrm{log}_{\mathrm{2}} \:\mathrm{3}\right)^{\mathrm{2}} >\left(\frac{\mathrm{3}}{\mathrm{2}}\right)^{\mathrm{2}} =\frac{\mathrm{9}}{\mathrm{4}}>\frac{\mathrm{8}}{\mathrm{4}}=\mathrm{2} \\ $$$$\Rightarrow\mathrm{log}_{\mathrm{2}} \:\mathrm{3}>\sqrt{\mathrm{2}} \\ $$$$ \\ $$$$\mathrm{27}<\mathrm{32} \\ $$$$\mathrm{3}^{\mathrm{3}} <\mathrm{2}^{\mathrm{5}} \\ $$$$\mathrm{3log}_{\mathrm{2}} \:\mathrm{3}<\mathrm{5} \\ $$$$\mathrm{log}_{\mathrm{2}} \:\mathrm{3}<\frac{\mathrm{5}}{\mathrm{3}} \\ $$$$\left(\mathrm{log}_{\mathrm{2}} \:\mathrm{3}\right)^{\mathrm{2}} <\left(\frac{\mathrm{5}}{\mathrm{3}}\right)^{\mathrm{2}} =\frac{\mathrm{25}}{\mathrm{9}}<\frac{\mathrm{27}}{\mathrm{9}}=\mathrm{3} \\ $$$$\Rightarrow\mathrm{log}_{\mathrm{2}} \:\mathrm{3}<\sqrt{\mathrm{3}} \\ $$
Commented by som(math1967) last updated on 27/Feb/21
![ok sir](https://www.tinkutara.com/question/Q134044.png)
$${ok}\:{sir} \\ $$