we can answer this problem asking to express the complex number -6i in trigonometric form. first thing to do is to evaluate the given expressions
cos 0 is 1
sin 0 is 0
sin 180 is 0
cos 180 is -1
cos 270 is 0
sin 270 is -1
sin 90 is 1
cos 90 is 0.
Hence the answer to this problem is B.6(cos 270° + i sin 270°)
