Question

tanA+tanB/coA+cotB=tanAtanB

Answer 1

Answer:

(tan A+tan B) / (cot A+cot B)

⇒(tan A+tan B) / (1/tan A+1/tan B)

⇒(tan A +tan B) / (tan A+tan B / tan A·tan B)

⇒(tan A+tan B) / (tan A·tan B / tan A+tan B)

⇒tan A ·tan B

hence proved