Question

What is the Cosine of α if a = 3.80, b = 3.90, c = 29.50?

Answer 1

Cosine of α = (a^2 + b^2 - c^2) / (2ab)

Cosine of α = (3.80^2 + 3.90^2 - 29.50^2) / (2 * 3.80 * 3.90)

Cosine of α = 0.945