Projection formula:
Prove that ` a= b cos C +c cos B. `

Prove that a cos A+b cos B+c cos C<=s

In triangle ABC , prove that (1) a=b cos C+c cos B (2) b=a cos C+c cos A .

In any DeltaABC , prove that : (cos A)/(b cos C + c cos B) + (cos B)/(c cos A + a cos C) + (cos C)/(a cos B + b cos A) = (a^2 + b^2 + c^2)/(2abc)

In any DeltaABC , prove that : a cos A + b cos B + c cos C = 2a sin B sin C

In any triangle ABC, prove that : (b + c) cos A + (c + a) cos B + (a + b) cos C=a+b+c .

In /_\ABC ,Prove that a cos A + b cos B + c cos C = 2a sin B sin C

In any triangle ABC, prove that: a cos A+b cos B+c cos C=2a sin B sin C

In any Delta ABC, prove that : (cos A)/(b cos C+c cos B)+(cos B)/(c cos A+a cos C)+(cos C)/(c cos B+b cos A)=(a^(2)+b^(2)+c^(2))/(2abc)

For any triangle ABC,prove that a cos A+b cos B+c cos C=2a sin B sin C

In any Delta ABC, prove that :a cos A+b cos B+c cos C=2a sin B sin C