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.