11-2

1+i square root of 3

r=square root of 162+square root of 3^2                                  theta=tan^-1(square root of 3)
r=square root of 4                                                                     theta=60 degrees, and 240 degrees
r=+/-2

First you use the formula r= square root of x^2 +y^2.  When you solve that, you get the square root of 4.  The square root of 4 equals plus or minus 2.  Once you solved that, you use the other formula.  The other formula is theta equals tan of negative 1 of y/x.  Now you have tan^-1(square root of 3/1).  That is tan^-1(square root of 3).  From the trig chart, we know that tan of square root of 3 equals 60 degrees.  Now you use the unit circle to find the other angle.  Tan is positive in quadrant three as well as quadrant one.  So now you add 180 to 60 and you get 240 degrees.  So 60 degrees and 240 degrees are your two answers.