If $\alpha, \beta \in \mathbb{R}$ are such that $1-2i$ (where $i^{2}=-1$) is a root of $z^{2}+\alpha z+\beta=0$,then $(\alpha-\beta)$ is equal to ..... .

  • A
    $-3$
  • B
    $-7$
  • C
    $7$
  • D
    $3$

Explore More

Similar Questions

What is the geometric mean of the roots of the equation $x^2 - 18x + 9 = 0$?

If the sum of the roots of the equation $x^2 + px + q = 0$ is equal to the sum of their squares,then

If $a(p + q)^2 + 2bpq + c = 0$ and $a(p + r)^2 + 2bpr + c = 0$,then $qr$ =

If $\alpha, \beta$ are the roots of $a x^2+b x+c=0$,then the quadratic equation whose roots are $\sqrt{5} \alpha, \sqrt{5} \beta$ is

If one root of the cubic equation $x^3-7x^2+36=0$ is double of another,then the number of negative roots is

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo