Question:
Solve the system of equations Re (z2) = 0, |z| = 2.
Solution:
According to the question,
We have,
Re (z2) = 0, |z| = 2
Let z = x + iy.
Then, |z| = √(x2 + y2)
Given in the question,
√(x2 + y2) = 2
⇒ x2 + y2 = 4 … (i)
z2 = x2 + 2ixy – y2
= (x2 – y2) + 2ixy
Now, Re (z2) = 0
⇒ x2 – y2 = 0 … (ii)
Equating (i) and (ii), we get
⇒ x2 = y2 = 2
⇒ x = y = ±√2
Hence, z = x + iy
= ±√2 ± i√2
= √2 + i√2, √2 – i√2, –√2 + i√2 and –√2 – i√2
Hence, we have four complex numbers.