Complex Numbers And Quadratic Equations question 716
Question: The roots of the equation $ {x^{2/3}}+{x^{1/3}}-2=0 $ are [UPSEAT 2004]
Options:
A) 1, 4
B) $ 1,-4 $
C) $ 1,-8 $
D) 1, 8
Show Answer
Answer:
Correct Answer: C
Solution:
$ {x^{2/3}}+{x^{1/3}}-2=0 $ Þ $ {{({x^{1/3}})}^{2}}+1({x^{1/3}})-2=0 $ Let $ a={x^{1/3}}, $ then $ a^{2}+a-2=0 $ Þ $ a=1,-2 $ Hence $ x=1,-8 $ (by $ a={x^{1/3}} $ ).
BETA
