I have noooooo idea how to do these types of problems. I missed the lecture when we were on this topic and now I'm lost. Can anyone explain to me how to do these type, step by step?

1. Express the complex number in polar form:

a) (e^i*pi/3)^2

b) (2+3i) + (-5-7i)

c) 4root(10e^i*pi/2)

d) (2i)^3 - (2i)^2 + 2i - 1

Please help...