16 points. brainliest to best answer. Can someone teach me the law of cosigns in geometry?

If a =6, what is the value of 2a(3b + 5c)?

∠1 and ∠2 are complementary. ∠1=x°∠2=(3x+30)° select from the drop down menu to correctly answer the question. what is the value of x? . a.15 b.25 c.30 d.40 e.55

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .