Question

. Verify the Pythagorean Identity.

Answer 1

convert to sines and cosines:-
1 + cot^2 x
= 1 + cos^2 x / sin^2x

= sin^2 x + cos^2 x
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sin^2 x

but sin^2 x + cos^2 x = 1

so this = 1 / sin^2x which is the same as csc^2 x