Question

If tanb=nsinacosa / 1-nsin2a, prove that tan(a-b)= (1-n)tana

Answer 1

tan(a-b)=tana-tanb/1+tanatanb
=(sina/cosa-nsinacosa/1-nsin2a)/1+sina/cosa×nsinacosa/1-nsin2a
=sina-nsin3a-nsinacos2a/cosa(1-nsin2a)+nsin2acosa
=sina-nsin3a-nsina(1-sin2a)/cosa-nsin2acosa+nsinacos2a
=sina-nsin3a-nsina+nsin3a/cosa
=sina-nsin3a-nsina/cosa
=sina(1-n)/cosa
=(1-n)tana

hope it helps
CHEERS!!

Answer 2

Answer

Hope it helps!!!