Try A) 60 degrees; 1/2. Your answer was incorrect because cos(60 degrees) is 1/2, cos(30 degrees) is square root 3 /2 not 1 or square root 2 /2
It is 2i I standing for imaginary since it is a negative
square root of -1×4
4 square rooted is 2
and a negative number square rooted is i
