Let (𝐺, .) be a group of all non-zero complex no. Show that H={a+ib:a^2+b^2=1} is a subgroup of 𝐺.

#subgroup
Let 𝐺 be a group of all non-zero complex numbers under multiplication. Show that 𝑯={𝒂+𝒊𝒃 : 𝒂^𝟐+𝒃^𝟐=𝟏} is a subgroup of 𝐺.

[farihasabeen]

Sr what to do if the condition for H is a²≥b and we've to show that H is normal in G or not