Complex Numbers And Quadratic Equations question 617
Question: If a and b are roots of $ x^{2}-px+q=0 $ , then $ \frac{1}{a}+\frac{1}{b}= $ [Orissa JEE 2004]
Options:
A) $ \frac{1}{p} $
B) $ \frac{1}{q} $
C) $ \frac{1}{2p} $
D) $ \frac{p}{q} $
Show Answer
Answer:
Correct Answer: D
Solution:
Roots of given equation $ x^{2}-px+q=0 $ is $ a $ and $ b $ i.e., $ a+b=p $ ??(i) and $ ab=q $ ??(ii) Then $ \frac{1}{a}+\frac{1}{b}=\frac{a+b}{ab}=\frac{p}{q} $ .
BETA
