妙妙貓

I'm not quite sure what to do with this question (as can see in my attempted working out).

I apologise, I'm not sure why I am unable to upload the attachment. The question is as follows:

Suppose that the complex number z lies on the unit circle and 0 ≤ arg(z) ≤ pi/2. Prove that 2arg(z+1)=arg(z)

I drew a diagram with a quarter of a unit circle in quadrant 1 with a moving point z, which I extended with a horizontal line 1 unit to the right. But from there, I'm not quite sure what to do next.

[ 本帖最後由 妙妙貓 於 2022-4-5 02:32 PM 編輯 ]

風之男

I don't see any attachments. Could you please check and reattach?