Question

Calcule:

Sen (x - 30°)
Pfvr me ajudem

Answer 1

sabendo que:

$\sin(x - y) = \sin(x) \cos(y) - \sin(y) \cos(x)$

então:

$\sin(x - 30) = \sin(x) \cos(30) - \sin(30) \cos(x)$

como:

$\sin(30) = \frac{1}{2} \\ \cos(30) = \frac{ \sqrt{3} }{2}$

assim:

$\sin(x - 30) = \frac{ \sqrt{3} }{2} \sin(x) - \frac{1}{2} \cos(x) \\ \sin(x - 30) = \frac{ \sqrt{3} \times \sin(x) - \cos(x) }{2}$