If a2, b2, c2 are in A.P., prove that 1/b+c, 1/c+a, 1/a+b is also in AP. Also prove the converse is - Brainly.in
Show that in triangle ABC we have cosA=b2+c2-a2/2bc | Homework.Study.com
Prove the following identities : |((b+c)^2,b^2,bc)((c+a)^2,b^2,ca)((a+b)^2,c^2,ab)|=(a-b) = (a - b) (b - c) (c - a) (a + b+ c)(a2 + b2 + c2) - Sarthaks eConnect | Largest Online Education