Question

Which of the following complex numbers is 2- equivalent to ? (Note: i= -1) 2+i

Answer 1

Answer:

A

Step-by-step explanation:

Given

$\frac{2-i}{2+i}$

Multiply the numerator/ denominator by the conjugate of the denominator.

The conjugate of 2 + i is 2 - i , then

= $\frac{(2-i)(2-i)}{(2+i)(2-i)}$ ← expand numerator/ denominator using FOIL

= $\frac{4-4i+i^2}{4-i^2}$  [ i = $\sqrt{-1}$ ⇒ i² = - 1 ]

= $\frac{4-4i-1}{4+1}$

= $\frac{3-4i}{5}$

= $\frac{3}{5}$ - $\frac{4}{5}$ i → A

Answer 2

Answer:

i = the square root of -1

Step-by-step explanation: