Question: If $ x=\sqrt{a\sqrt[3]{b\sqrt{a\sqrt[3]{b…..\infty }}}}, $ then the value of x is
Options:
A) $ \sqrt[5]{ab^{3}} $
B) $ \sqrt[5]{a^{5}b} $
C) $ \sqrt[3]{a^{3}b} $
D) $ \sqrt[5]{a^{3}b} $
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Answer:
Correct Answer: D
Solution:
- Given, $ x=\sqrt{a\sqrt[3]{b\sqrt{a\sqrt[3]{b…..\infty }}}} $
By squaring both sides,
$ x^{2}=a\sqrt[3]{b\sqrt{a\sqrt[3]{b…..\infty }}} $
By cubing both sides,
$ x^{6}=a^{3}b\sqrt{a\sqrt[3]{b…..\infty }} $
$ \Rightarrow $ $ x^{6}=a^{3}bx $
$ \Rightarrow $ $ x^{6}-a^{3}bx=0 $
$ \Rightarrow $ $ x,(x^{5}-a^{3}b)=0 $
$ \Rightarrow $ $ x=0, $ $ x^{5}=a^{3}b $
$ \therefore $ $ x=\sqrt[5]{a^{3}b} $