Question

if A+B =45deggres, then
(cot A-1) (cotB-1) =2
​

Answer 1

Step-by-step explanation:

Given A+B=45

∘

⟹cot(A+B)=cot45

∘

⟹

cotA+cotB

cotAcotB−1

=1

⟹cotA+cotB−cotAcotB=−1

⟹cotA+cotB−cotAcotB−1=−2

⟹cotA(1−cotB)−(1−cotB)=−2

⟹(cotA−1)(1−cotB)=−2

⟹(cotA−1)(cotB−1)=2

So m=2