Sorry but it's a little hard to write the question out! I have the working on paper but I can't upload it. Ok so first you need to multiply out the brackets to make it a little easeier to look at and obtain the form z^4 = 2+2sqrt(3)i.From here you can get a modulus of 4 and an angle of 1/3pi rad using a^2+b^2=C^2 and tan^-1 of b/a respectivley.Remember that a+bi = mode^argi where mod is the modulus (sqrt(a^2+b^2)) and arg is the argument (tan^-1(b/a)).From here use the identity to get exponential form and calculate Z, Z^4 = 4e^(1/3pi*i) so Z=4^(1/4)exp((1/3pi+2kpi) i/4) = sqrt(2)(e^(1/12pi*i), e^(7/12pi