1/1+cot^2x + 1/1+tan^2 x = 1

IdenTitaS TriGonoMetRi

1 + cot² x = csc² x = 1/sin² x
1 + tan² x = sec² x = 1/cos² x

1/(1 + cot² x) + 1/(1 + tan² x)
= 1/(1/sin² x) + 1/(1/cos² x)
= sin² x + cos² x
= 1
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