Question

One root of the equation $x^2-ix-(1+i)=0$ is $1+i$, where $i=\sqrt{-1}$, then other root is

• A. $1-i$
• B. $-1-i$
• C. $-1+i$
• D. $-1$

Answer 1

The correct option is D $-1$

Let roots be $\alpha =1+i$ and $\beta$
$\alpha +\beta =i$
$\Rightarrow 1+i+\beta =i$
$\beta =-1$
Hence, option 'D' is correct.