Question

If $a\in R\&b\in R$, then the equation $x^2-abx-a^2=0$ has ________.

• A. One positive and one negative root
• B. Both positive
• C. Both negative
• D. Can't say

Answer 1

The correct option is A

One positive and one negative root

We have seen that product of the roots is = $\frac{c}{a}$
So, the product will be = - $a^2$
Which is negative as $a\in R$
Since product of roots are negative, the roots have to be of opposite sign.