Complex Numbers And Quadratic Equations question 815
Question: If the sum of two of the roots of $ x^{3}+px^{2}+qx+r=0 $ is zero, then pq = [EAMCET 2003]
Options:
A) - r
B) r
C) 2 r
D) - 2 r
Show Answer
Answer:
Correct Answer: B
Solution:
Given that, $ \alpha +\beta =0 $ $ \alpha +\beta +\gamma =-p\Rightarrow \gamma =-p $ Substituting $ \gamma =-p $ in the given equation Þ $ -p^{3}+p^{3}-pq+r=0\Rightarrow pq=r $ .
BETA
