A line making angles 45° and 60° with the positive directions of the axes of x and y makes with the positive direction of z-axis, an angle of
60°
120°
60° or 120°
None of these
If x = , then is equal to
n2(y2 - 4)
n2(4 - y2)
n2(y2 + 4)
None of these
C.
n2(y2 + 4)