Question

answer me fast emergency ​

Answer 1

Answer:

Step-by-step explanation:

From projection formula a cosB + b cos A = C   and cosA = (b2 + c2 - a2)/2bc So L.H.S. = (b2 + c2 - a2)/abc + (c2 + a2 - b2)/abc + (a2 + b2 - c2)/abc = (a2 + b2 + c2)/abc