यदि `A+B+C =pi,` सिद्ध कीजिए कि
`cot.(A)/(2)+cot.(B)/(2)+cot.(C)/(2)=cot.(A)/(2)cot.(B)/(2)cot.(C)/(2)`

Explanation

हम जानते हैं कि `A+B+C=pi`
`rArr" "(A+B)/(2)=(pi)/(2)-(C)/(2)`
`rArr" "cot((A+B)/(2))=cot((pi)/(2)-(C)/(2))=tan.(C)/(2)`
`rArr" "(cot.(A)/(2)cot.(B)/(2)-1)/(cot.(A)/(2)+cot.(B)/(2))=(1)/(cot.(C)/(2))`
`rArr" "cot.(A)/(2)cot.(B)/(2)cot.(C)/(2)-cot.(C)/(2)=cot.(A)/(2)+cpot.(B)/(2)`
`rArr" "cot.(A)/(2)cot.(B)/(2)cot.(C)/(2)=cot.(A)/(2)+cot.(B)/(2)+cot.(C)/(2)`