Complex Numbers And Quadratic Equations question 771
Question: If $ l,m,n $ are real and $ l\ne m $ , then the roots of the equation $ (l-m)x^{2}-5(l+m)x-2(l-m)=0 $ are [IIT 1979; RPET 1983]
Options:
A) Complex
B) Real and distinct
C) Real and equal
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
Given equation is $ (l-m)x^{2}-5(l+m)x-2(l-m)=0 $ Its discriminant $ D=25 $ $ {{(l+m)}^{2}}+8 $ $ {{(l-m)}^{2}} $ which is positive, since $ l,m,n $ are real and $ l\ne m $ . Hence roots are real and distinct.
BETA
