Sorry, I should've put the whole problem on here. The problem states:
"By writing the individual factors on the left in exponential form, performing the needed operations, and finally changing back to rectangular coordinates, show that
"
This can be easily shown by just multiplying top and bottom by the conjugate of the denominator, but I have to do it how the directions say. I know how to convert 5i into exponential form, but converting 2+i into exponential form has proven to be more problematic since arctan(1/2) isn't very simple.