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Question-193793




Question Number 193793 by Mingma last updated on 20/Jun/23
Commented by MM42 last updated on 20/Jun/23
yes.you are right  it was my mistake.thank you
$${yes}.{you}\:{are}\:{right} \\ $$$${it}\:{was}\:{my}\:{mistake}.{thank}\:{you} \\ $$
Commented by Frix last updated on 20/Jun/23
1.61053599<x<1.63195612
$$\mathrm{1}.\mathrm{61053599}<{x}<\mathrm{1}.\mathrm{63195612} \\ $$
Commented by Frix last updated on 20/Jun/23
⌊3.14⌋=3 but ⌈3.14⌉=4    x=1.62  ⌊1.62^(⌈1.62^(⌈1.62⌉) ⌉1.62) ⌋=⌊1.62^(⌈1.62^2 ⌉1.62) ⌋=  =⌊1.62^(3×1.62) ⌋=⌊10.429...⌋=10
$$\lfloor\mathrm{3}.\mathrm{14}\rfloor=\mathrm{3}\:\mathrm{but}\:\lceil\mathrm{3}.\mathrm{14}\rceil=\mathrm{4} \\ $$$$ \\ $$$${x}=\mathrm{1}.\mathrm{62} \\ $$$$\lfloor\mathrm{1}.\mathrm{62}^{\lceil\mathrm{1}.\mathrm{62}^{\lceil\mathrm{1}.\mathrm{62}\rceil} \rceil\mathrm{1}.\mathrm{62}} \rfloor=\lfloor\mathrm{1}.\mathrm{62}^{\lceil\mathrm{1}.\mathrm{62}^{\mathrm{2}} \rceil\mathrm{1}.\mathrm{62}} \rfloor= \\ $$$$=\lfloor\mathrm{1}.\mathrm{62}^{\mathrm{3}×\mathrm{1}.\mathrm{62}} \rfloor=\lfloor\mathrm{10}.\mathrm{429}…\rfloor=\mathrm{10} \\ $$
Commented by Mingma last updated on 20/Jun/23
perfect ��
Answered by mr W last updated on 22/Jun/23
if x≥2:   ⌊x^(⌈x^(⌈x⌉) ⌉x) ⌋≥2^(2^2 ×2) =2^8 =256 >10  if x=1:  ⌊x^(⌈x^(⌈x⌉) ⌉x) ⌋=1<10  ⇒1<x<2, i.e. ⌈x⌉=2  if x≤(√2):  ⌊x^(⌈x^(⌈x⌉) ⌉x) ⌋≤⌊((√2))^(2(√2)) ⌋=2<10  ⇒x>(√2)  ⌈x^(⌈x⌉) ⌉=3, i.e. 2<x^2 ≤3 ⇒x≤(√3)  ⌊x^(⌈x^(⌈x⌉) ⌉x) ⌋=⌊x^(3x) ⌋=10  10≤x^(3x) <11  10^(1/3) ≤x^x <11^(1/3)   ⇒((ln 10)/(3 W(((ln 10)/3))))≤x<((ln 11)/(3 W(((ln 11)/3)))) ✓    i.e. ≈1.61053599≤x<≈1.63195611
$${if}\:{x}\geqslant\mathrm{2}:\: \\ $$$$\lfloor{x}^{\lceil{x}^{\lceil{x}\rceil} \rceil{x}} \rfloor\geqslant\mathrm{2}^{\mathrm{2}^{\mathrm{2}} ×\mathrm{2}} =\mathrm{2}^{\mathrm{8}} =\mathrm{256}\:>\mathrm{10} \\ $$$${if}\:{x}=\mathrm{1}: \\ $$$$\lfloor{x}^{\lceil{x}^{\lceil{x}\rceil} \rceil{x}} \rfloor=\mathrm{1}<\mathrm{10} \\ $$$$\Rightarrow\mathrm{1}<{x}<\mathrm{2},\:{i}.{e}.\:\lceil{x}\rceil=\mathrm{2} \\ $$$${if}\:{x}\leqslant\sqrt{\mathrm{2}}: \\ $$$$\lfloor{x}^{\lceil{x}^{\lceil{x}\rceil} \rceil{x}} \rfloor\leqslant\lfloor\left(\sqrt{\mathrm{2}}\right)^{\mathrm{2}\sqrt{\mathrm{2}}} \rfloor=\mathrm{2}<\mathrm{10} \\ $$$$\Rightarrow{x}>\sqrt{\mathrm{2}} \\ $$$$\lceil{x}^{\lceil{x}\rceil} \rceil=\mathrm{3},\:{i}.{e}.\:\mathrm{2}<{x}^{\mathrm{2}} \leqslant\mathrm{3}\:\Rightarrow{x}\leqslant\sqrt{\mathrm{3}} \\ $$$$\lfloor{x}^{\lceil{x}^{\lceil{x}\rceil} \rceil{x}} \rfloor=\lfloor{x}^{\mathrm{3}{x}} \rfloor=\mathrm{10} \\ $$$$\mathrm{10}\leqslant{x}^{\mathrm{3}{x}} <\mathrm{11} \\ $$$$\mathrm{10}^{\frac{\mathrm{1}}{\mathrm{3}}} \leqslant{x}^{{x}} <\mathrm{11}^{\frac{\mathrm{1}}{\mathrm{3}}} \\ $$$$\Rightarrow\frac{\mathrm{ln}\:\mathrm{10}}{\mathrm{3}\:{W}\left(\frac{\mathrm{ln}\:\mathrm{10}}{\mathrm{3}}\right)}\leqslant{x}<\frac{\mathrm{ln}\:\mathrm{11}}{\mathrm{3}\:{W}\left(\frac{\mathrm{ln}\:\mathrm{11}}{\mathrm{3}}\right)}\:\checkmark \\ $$$$ \\ $$$${i}.{e}.\:\approx\mathrm{1}.\mathrm{61053599}\leqslant{x}<\approx\mathrm{1}.\mathrm{63195611} \\ $$
Commented by Frix last updated on 26/Jun/23
Great!
$$\mathrm{Great}! \\ $$

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