Find the modulus of each of the following complex numbers and hence express each of them in polar form: –2
Let Z = -2 = r(cosθ + isinθ)
Now, separating real and complex part, we get
-2 = rcosθ………. eq.1
0 = rsinθ …………eq.2
Squaring and adding eq.1 and eq.2, we get
4 = r2
Since r is always a positive no.,therefore,
r = 2,
hence its modulus is 2.
now, dividing eq.2 by eq.1 , we get,
Tanθ = 0
Since cosθ = -1, sinθ = 0 and tanθ = 0. Therefore the lies in second quadrant.
Tanθ = 0, therefore θ = π
Representing the complex no. in its polar form will be
Z = 2(cosπ + isinπ)