Question

The value of p and q$p\ne 0,q\ne 0$ for which p,q are the roots of the equation: $x^2+px+q=0$ are

• A. p = 1, q = -2
• B. p = -1, q = -2
• C. p = -1, q =2
• D. p = 1, q = 2

Answer 1

The correct option is C

p = -1, q =2

It is given that p and q$p\ne 0,q\ne 0$ are the roots of the equation.

$x^2+px+q=0$

$\therefore$ Sum of the roots p + q = -q $\Rightarrow 2p+q=0$ ...(i) Products of roots = pq = q $\Rightarrow q(p-1)=0$

$\Rightarrow p=1,q=0q\ne 0$

Now substituting p = 1 (i), we get 2(1)+q = 0 2(1)+q=0

$\Rightarrow q=-2$