(i)
or
or
The roots of the given equation are
(ii)
apply discriminant rule,
8 + 14i = 49 – 1 + 14i
So,
48 + 14i = 49 + i2 + 14i [∵ i2 = –1]
= 72 + i2 + 2(7)(i)
= (7 + i)2 [Since, (a + b)2 = a2 + b2 + 2ab]
By using the result 48 + 14i = (7 + i) 2, we get
x = 2 + 3i or 3 – 4i
∴ The roots of the given equation are 3 – 4i, 2 + 3i