cot(x)cos(x) + csc(x)sin2(x)
= [cos(x)/sin(x)]cos(x) + [1/sin(x)]sin2(x) <-- Quotient Identity and Reciprocal Identity
= cos2(x)/sin(x) + sin2(x)/sin(x)
= [cos2(x)+sin2(x)]/sin(x)
= 1/sin(x) <-- Pythagorean Identity
= csc(x) <-- Quotient Identity
Hope this helped!