Question

Se senx.cos 40*+sen 40*.cosx=sen 70* então:

Answer 1

senxcos40 + sen40°cosx = sen70°

sen(x + 40°) = sen70°

Se senα = senβ => α = β + 2kπ ou α = π - β + 2kπ

x + 40°= 70° + k.360°

x = 70° - 40° + k .360°

x = 30° + k.360°
ou
x + 40 = (180° - 70°) + k.360°

x + 40 = 110° + k . 360°

x = 70° + k.360°

S = { x ∈ IR/ x = 30° + k.360° ou x = 70° + k.360°, k ∈ Z }

Answer 2

Bom dia Vithtiger

sen(x)*cos(40) + sen(40)*cos(x) = sen(x + 40)

sen(x + 40) = sen(70)

x + 40 = 70
x = 70 - 40 

x = 30° + k*360