complex numbers

1. (i) find the modulus and argument(rad and degree) of the complex z=5j
(ii) express 5j in the form in polar form

2.convert the following complex number (3j) into polar form.

3. if z1=5angle(pie/6), and z2=4angle(-pie/4),
find (i)z1z2
(ii)z1/z2
(iii)z2/z1

4. prove that, if (z-4j)/(z+3) is purely real, the locus of the point which represents z in the Argand diagram is a straight line.