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Question

Mathematics Question on Complex Numbers and Quadratic Equations

If α\alpha and β\beta are (α<β)(\alpha < \beta) the roots of the equation x2+bx+c=0,x^2+bx+c=0, where c<0<bc < 0 < b,the

A

0

B

α<0\alpha<0

C

α\alpha

D

α<0\alpha<0

Answer

α<0\alpha<0

Explanation

Solution

The correct answer is B:α<0\alpha<0
Equation is x^2+bx++c=0,$$c<0<b
roots of this quadratic equation are α,β(α<β)\alpha,\beta(\alpha<\beta)
So,we have,
α+β=b,,αβ=c\alpha+\beta=-b,\,\,\,\,,\,\,\,\,-\alpha\beta=c here, c<0,αβ<0c<0,\alpha\beta<0
For this case
b>0  (given)b>0\space (given)
\therefore $$\alpha+\beta<0
α=positive,β=negative,β<α\alpha=positive,\beta=negative,|\beta|<|\alpha|
\therefore$$\alpha<0\space and \space 0<\beta
\therefore$$\alpha<0<\beta<|\alpha|
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