Question

calcule e = (sen 15° + cos 75°)cos 15°

Answer 1

sen 15° = sen ( 45° - 30°) = sen©, 45.cós 30° - sen 30°.cos 45° = √2/4.(√3 -1)

cos 15° = cos (45° - 30°) = √2/4.(√3 - 1)

e = {(√2/4.(√3 - 1) + √2/4.(√3 - 1)}.cos √2/4.(√3 -1)
e = 2 - √3/2
Bons Estudos
kelemen