Question

If $\alpha ,\beta$ are roots of $4x^2+2x-1=0$, then $\beta$ is equal to

• A. $-\frac{1}{4\alpha }$
• B. $-\frac{1}{2\alpha }$
• C. $-\frac{1}{\alpha }$
• D. $-\frac{1}{3\alpha }$
• E. $\frac{1}{\alpha }$

Answer 1

The correct option is A $-\frac{1}{4\alpha }$

Given equation
$4x^2+2x-1=0$

Roots of the equation are $\alpha$ and $\beta$

$\therefore \alpha +\beta =\frac{-b}{a}=\frac{-2}{4}=-\frac{1}{2}$

$\alpha \beta =\frac{c}{a}=-\frac{1}{4}$

$\therefore \beta =-\frac{1}{4\alpha }$