Convert to trigonometric form

The form is :   z =  r [ cos θ  + i sin θ]

r = √[ ( -2 )^2  + (-2)^2 ]   =  √ 8  = 2√2

θ   is in the 3rd quadrant  and  can be found, thusly

arctan (-2/-2)  = arctan(1)   =  45°   = pi/4

But....since this is in the 3rd quadrant, the angle becomes  5pi/4

So...the trigonometric (polar) form is  :

z = 2√2 [ cos 5pi/4 + i sin 5pi/4 ]