Step-by-step explanation:
From Trig
1 + tan²x = Sec²x
Also
Sec²x = 1/cos²x
Now
Cot²x = 1/tan²x = cos²x/sin²x
Putting all together
Cot²x(1+tan²x)
= Cot²x(sec²x)
= cos²x/sin²x(1/cos²x)
cos²x on the numerator and that one the denominator cancels out
we have
= 1/sin²x
From Trig
1/sin²x = cosec²x
So Our Answer = cosec²x.
