Question

Qual o valor numérico de y = sen 15 + sen 75

Answer 1

y = sen15° + sen75° = sen(45° - 30°) + sen(45° + 30°) =
= sen45°cos30° - sen30°. cos45° + sen45°.cos30° + sen30°.cos45°=
= √2/2 . √3/2 - 1/2 .√2/2 + √2/2 . √3/2 + 1/2 . √2/2 =
= √6/4 - √2/4 + √6/4 + √2/4 = 2√6/4 = √6/2 = 1,2247 (aproximadamente)