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Question-61343




Question Number 61343 by bhanukumarb2@gmail.com last updated on 01/Jun/19
Answered by MJS last updated on 01/Jun/19
x=a−(1/(a−(1/(a−...))))  x=a−(1/x)  x^2 −ax+1=0  x=(a/2)±((√(a^2 −4))/2)  a=2207 ⇒ x=((2207±987(√5))/2)  (((2207±987(√5))/2))^(1/8) =(√(√(√((2207±987(√5))/2))))  step 1  (a±b(√5))^2 =((2207±987(√5))/2) ⇒ a=((47)/2), b=((21)/2)  step 2  (a±b(√5))^2 =((47±21(√5))/2) ⇒ a=(7/2), b=(3/2)  step 3  (a±b(√5))^2 =((7±3(√5))/2) ⇒ a=(3/2); b=(1/2)  result is  ((3±(√5))/2)
$${x}={a}−\frac{\mathrm{1}}{{a}−\frac{\mathrm{1}}{{a}−…}} \\ $$$${x}={a}−\frac{\mathrm{1}}{{x}} \\ $$$${x}^{\mathrm{2}} −{ax}+\mathrm{1}=\mathrm{0} \\ $$$${x}=\frac{{a}}{\mathrm{2}}\pm\frac{\sqrt{{a}^{\mathrm{2}} −\mathrm{4}}}{\mathrm{2}} \\ $$$${a}=\mathrm{2207}\:\Rightarrow\:{x}=\frac{\mathrm{2207}\pm\mathrm{987}\sqrt{\mathrm{5}}}{\mathrm{2}} \\ $$$$\sqrt[{\mathrm{8}}]{\frac{\mathrm{2207}\pm\mathrm{987}\sqrt{\mathrm{5}}}{\mathrm{2}}}=\sqrt{\sqrt{\sqrt{\frac{\mathrm{2207}\pm\mathrm{987}\sqrt{\mathrm{5}}}{\mathrm{2}}}}} \\ $$$$\mathrm{step}\:\mathrm{1} \\ $$$$\left({a}\pm{b}\sqrt{\mathrm{5}}\right)^{\mathrm{2}} =\frac{\mathrm{2207}\pm\mathrm{987}\sqrt{\mathrm{5}}}{\mathrm{2}}\:\Rightarrow\:{a}=\frac{\mathrm{47}}{\mathrm{2}},\:{b}=\frac{\mathrm{21}}{\mathrm{2}} \\ $$$$\mathrm{step}\:\mathrm{2} \\ $$$$\left({a}\pm{b}\sqrt{\mathrm{5}}\right)^{\mathrm{2}} =\frac{\mathrm{47}\pm\mathrm{21}\sqrt{\mathrm{5}}}{\mathrm{2}}\:\Rightarrow\:{a}=\frac{\mathrm{7}}{\mathrm{2}},\:{b}=\frac{\mathrm{3}}{\mathrm{2}} \\ $$$$\mathrm{step}\:\mathrm{3} \\ $$$$\left({a}\pm{b}\sqrt{\mathrm{5}}\right)^{\mathrm{2}} =\frac{\mathrm{7}\pm\mathrm{3}\sqrt{\mathrm{5}}}{\mathrm{2}}\:\Rightarrow\:{a}=\frac{\mathrm{3}}{\mathrm{2}};\:{b}=\frac{\mathrm{1}}{\mathrm{2}} \\ $$$$\mathrm{result}\:\mathrm{is} \\ $$$$\frac{\mathrm{3}\pm\sqrt{\mathrm{5}}}{\mathrm{2}} \\ $$
Commented by bhanukumarb2@gmail.com last updated on 01/Jun/19
thanks sir
$${thanks}\:{sir} \\ $$

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