Question

The root of the equation $2(1+i)x^2-4(2-i)x-5-3i=0$ which has greater modulus is

• A. $\frac{3-5i}{2}$
• B. $\frac{5-3i}{2}$
• C. $\frac{3-i}{2}$
• D. none

Answer 1

Answer: (A)

Given equation is $2(1+i)x^2-4(2-i)x-5-3i=0$
Roots $=\frac{4(2-i)\pm \sqrt{16(2-i{)}^2+8(1+i)(5+3i)}}{4(1+i)}$
$=\frac{4-i}{1+i}$ or $\frac{-i}{1+i}$
$=\frac{3-5i}{2}$ or $\frac{-1-i}{2}$