Question
Question: If α and β (α\<β) are the roots of the equation x<sup>2</sup> + bx + c = 0, where c \< 0 \< b, then...
If α and β (α<β) are the roots of the equation x2 + bx + c = 0, where c < 0 < b, then
A
0 <α<β
B
α< 0 < β< |α|
C
α<β< 0
D
α< 0 < |α| <β
Answer
α< 0 < β< |α|
Explanation
Solution
Given c < 0 < b and α + β = - b αβ = c
from (2), c < 0 ⇒ αβ < 0 ⇒ either α is –ve or β is –ve and second quantity is positive.
from (1), b > 0 ⇒ - b < 0 ⇒ α + β < 0 ⇒ the sum is negative
⇒ modules of nengative quantity is > modulus of positive
quantity but α < β is given.
Therefore, it is clear that α is negative and β is positive and modulus of α is greater than modulus of β ⇒ α < 0 β < |α|