Question

1. What is one of the square roots of 3+ 4i, where
i=-1?
(a) 2 + 1
(b) 2 - 1
(c) - 2+ i
(d)-3- i
​

Answer 1

Answer:

(c) - 2+ i is ans

Answer 2

Step-by-step explanation:

ANSWER

Let

3+4i

=

x

+i

y

Then (

3+4i

)

2

=(

x

+i

y

)

2

⇒3+4i=x−y+2i

xy

Comparing real part and imaginary part, we get

3=x−y and 2

xy

=4⇒xy=4

∴x+y=±5 ( As x



=−5;

x

is real part )

∴x=4,y=1⇒

x

=±2,y=±1

Hence square root is ±(2+i) .