Question

Prove (cot A +1)×(CotB+1)÷(Cot A×CotB)=2

Answer 1

Step-by-step explanation:

Cot (A+B) = (CotACotB-1)/(CotA + CotB )

We know......Cot(45)=1

so, 1=(CotACotB-1)/(CotA + CotB )

CotACotB-1)= (CotA + CotB )

CotACotB-cotA-cotB=1

adding 1 to both sides.....we get

(cotA-1)(cotB-1)=2......proved