The problem states, Show that: a) |e^(i*theta)| = 1. Now, the definition of e^(i*theta) makes this |cos(theta)+isin(theta)| If we choose any theta then this should be equal to 1. What can help me prove this? If I choose, say, pi/6 then it simplifies to |(sqrt(3))/2+i/2)| which doesn't seem to equal 1. b) BAR(e^(i*theta)) = e^(-i*theta) Here's what I think. The bar e^(i*theta) means that the definition is cos(theta)-isin(theta) and this can be rewritten as cos(-theta)+i*sin(-theta) which can be inputted back into the definition to see that e^(-i*theta) is correct.