Question

For the equation 10z2 - 4iz - m = 0 where z is a complex variable and i = √-1 , which of the following is true?

(a) Roots are purely imaginary for all negative real values of m

(b) Roots are not real for all complex numbers m

(c) Roots are purely imaginary for all positive real values of m

(d) of the above

Answer 1

Correct Option: (a)

Explanation:

Given:

10z2 - 4iz - m = 0

By using quadratic formula, we get

If m is negative, then D will also be negative.

So, the roots of z will be purely imaginary.