Q. If $a + ib = c + i d$ , then

1666 215 Complex Numbers and Quadratic Equations Report Error

A

$a^{2} + c^{2} = 0$

13%

B

$b^{2} + c^{2} = 0$

9%

C

$b^{2} + d^{2} = 0$

12%

D

$a^{2} + b^{2} = c^{2} + d^{2}$

66%

Solution:

$a + ib = c + i d$
$∴ ∣ a + ib ∣ = ∣ c + i d ∣$
$\Rightarrow a^{2} + b^{2} = c^{2} + d^{2}$