Complex Numbers And Quadratic Equations question 763

Question: The roots of the given equation $ 2(a^{2}+b^{2})x^{2}+2(a+b)x+1=0 $ are

Options:

A) Rational

B) Irrational

C) Real

D) Imaginary

Show Answer

Answer:

Correct Answer: D

Solution:

Given equation $ 2(a^{2}+b^{2})x^{2}+2(a+b)x+1=0 $ Let $ A=2(a^{2}+b^{2}),B=2(a+b) $ and $ C=1 $ $ B^{2}-4AC=4(a^{2}+b^{2}+2ab)-4.2(a^{2}+b^{2})1 $
$ \Rightarrow B^{2}-4AC=-4{{(a-b)}^{2}}<0 $ Thus given equation has imaginary roots.