Question

4. If A + B + C = k/pie
, k e Z Then prove that, (1) tanA + tanB + tanC = tanA · tanB · tanC (2) cotB · cotC + cotC · cotA + cotA · cotB = 1.​

Answer 1

Answer:

1

Step-by-step explanation:

In ΔABC , A+B+C=180∘

⟹A+B=180∘−C

⟹cot(A+B)=cot(180∘−C)

⟹cotA+cotBcotA.cotB−1=−cotC

⟹cotA.cotB−1=−cotA.cotC−cotB.cotC

⟹cotA.cotB+cotB.cotC+cotC.cotA=1