Question

sen(3x) - sen(5pi/4) = 0 Me ajudem ?(cálculos)

Answer 1

Resposta:

Explicação passo-a-passo:

$3x=5\pi/4$

$x=5\pi /12$$180----\pi \\x-----5\pi /12    x = 75°$

$3x=\frac{5\pi }{4}+2\pi n3x = 7\pi/4 + 2\pi n$$x=\frac{5\pi }{12}+\frac{2\pi n}{3}\\x=\frac{7\pi }{12}+\frac{2\pi n}{3}$

$sen (5\pi /4) = sen( \pi+ \pi/4)\\sen(a+b)= sen a cos b + sen b cos a\\sen(\pi) cos (\pi /4)+ sen(\pi/4)cos(\pi)\\ \\0\cdot \frac{\sqrt{2}}{2}+\left(-1\right)\frac{\sqrt{2}}{2} = -\sqrt{2} /2$