Triangle ABC has sides a, b, and c, and circumradius R. Prove that

\(b^2 + c^2 >= a^2 - R^2. \)

When does equality occur?

I haven't been able to do much on this problem but I think that I should use the law of cosines and law of sines in that order. Solutions would be appreciated. Thanks in advance!

Guest Aug 15, 2020