Question

The number of integral values of $m$, for which the roots of $x^2-2mx+m^2-1=0$ will lie between $-2$ and 4 is -

• A. 2
• B. 0
• C. 3
• D. 1

Answer 1

Answer: (C)

Hint : $x^2-2mx+m^2-1=0$
(i) $f(-2)>0$
(ii) $f(4)>0$
(iii) $D\ge 0$
(iv) $-2<\frac{-b}{2a}<4$
Common solution $m\in (-1,3)$