How do you verify the identity [(cosx cotx)/1-sin x]-1=cscx?

1 Answer
Jun 12, 2015

Is there a typo here? These are not equal.

http://www.wolframalpha.com/input/?i=Is+[cosxcotx+-+sinx]+-+1+%3D+cscx

With cotx = cosx/sinx and cscx = 1/sinx:

cosxcotx - sinx - 1 = cscx

cos^2x/sinx - sinx - 1 = cscx

cos^2x/sinx - sinx - 1 = 1/sinx

cos^2x - sin^2x - sinx = 1

cos^2x - sin^2x - sinx = sin^2x + cos^2x

cos^2x ne [sinx + 2sin^2x] + cos^2x