We have, z = i, i.e., z = 0 + 1⋅i
Let 0 = r cosθ …(i) and 1 = r sinθ …(ii)
Squaring and adding (i) and (ii), we get
r2(cos2θ+sin2θ) = 1 ⇒ r2 = 1 ⇒ r = 1
∴ cosθ = 0, sinθ = 1
⇒ cos θ = cos

π

2

, sin θ = sin

π

2

Here, cos θ = 0 and sin θ > 0
∴ θ lies in first quadrant.
∴ θ =

π

2

∴ The required polar form is z = 1 (cos

π

2

+isin

π

2

)