Question #3f97c
1 Answer
Jan 12, 2018
The RHS is more complex, so let us start with this:
# RHS = csc^2x/ (csc^2x - 2) #
# \ \ \ \ \ \ \ \ = (1/sin^2x)/ (1/sin^2x - 2) #
# \ \ \ \ \ \ \ \ = (1/sin^2x)/ ((1-2sin^2x)/sin^2x) #
# \ \ \ \ \ \ \ \ = 1 / (1-2sin^2x) #
# \ \ \ \ \ \ \ \ = 1 / (cos2x) #
# \ \ \ \ \ \ \ \ = sec2x \ \ \ # QED
