Hi Kennedy,
You can use the trigonometric identities, sin2x + cos2x =1 and tangent x = sin x/cos x, cotangent x = cos x/sin x and substitute them in to simplify:
sin2x X (1 + cos2x / sin2x) = 1 find a common denominator for the terms in parenthesis.
sin2x(sin2x / sin2x + cos2x / sin2x) =1
sin2x(1 / sin2x) =1
1=1
I hope this method is helpful by substituting in trigonometric identities. Feel free to contact me if you have questions.