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Question-167027




Question Number 167027 by Tawa11 last updated on 04/Mar/22
Commented by cortano1 last updated on 05/Mar/22
  { ((log _8 (p+2)+log _8 q=r−(1/3))),((log _8 (p−2)−log _8 q=2r+1)) :}  ⇒(1)+(2)≡ log _8 (p^2 −4)=3r+(2/3)  ⇒p^2 −4=8^(3r+(2/3))   ⇒p^2 =4+2^(9r+2)   ⇒p^2 =4+4.512^r   ⇒p^2 =4(1+512^r )  ⇒p =2(√(1+512^r ))
$$\:\begin{cases}{\mathrm{log}\:_{\mathrm{8}} \left(\mathrm{p}+\mathrm{2}\right)+\mathrm{log}\:_{\mathrm{8}} \mathrm{q}=\mathrm{r}−\frac{\mathrm{1}}{\mathrm{3}}}\\{\mathrm{log}\:_{\mathrm{8}} \left(\mathrm{p}−\mathrm{2}\right)−\mathrm{log}\:_{\mathrm{8}} \mathrm{q}=\mathrm{2r}+\mathrm{1}}\end{cases} \\ $$$$\Rightarrow\left(\mathrm{1}\right)+\left(\mathrm{2}\right)\equiv\:\mathrm{log}\:_{\mathrm{8}} \left(\mathrm{p}^{\mathrm{2}} −\mathrm{4}\right)=\mathrm{3r}+\frac{\mathrm{2}}{\mathrm{3}} \\ $$$$\Rightarrow\mathrm{p}^{\mathrm{2}} −\mathrm{4}=\mathrm{8}^{\mathrm{3r}+\frac{\mathrm{2}}{\mathrm{3}}} \\ $$$$\Rightarrow\mathrm{p}^{\mathrm{2}} =\mathrm{4}+\mathrm{2}^{\mathrm{9r}+\mathrm{2}} \\ $$$$\Rightarrow\mathrm{p}^{\mathrm{2}} =\mathrm{4}+\mathrm{4}.\mathrm{512}^{\mathrm{r}} \\ $$$$\Rightarrow\mathrm{p}^{\mathrm{2}} =\mathrm{4}\left(\mathrm{1}+\mathrm{512}^{\mathrm{r}} \right) \\ $$$$\Rightarrow\mathrm{p}\:=\mathrm{2}\sqrt{\mathrm{1}+\mathrm{512}^{\mathrm{r}} } \\ $$

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