1. The problem statement, all variables and given/known data If z = cis @ where @ is acute, determine the modulus and argument of z-1 2. Relevant equations 3. The attempt at a solution As the moudlus of z is 1 z lies on the unit circle. And I can not think of anything more. I drew a graph to see how z-1 seems like in graph and stucked. Help me please!