Question

utilizando os valores dos arcos notáveis calcule:
a) sen 150° e cos 150°
b)cos pi/2 e sen pi/2
c)cos 3pi/2 e sen 3pi/2
d) cos e sen de pi
e) cos 2pi e sen 2 pi

Answer 1

a) $\sin 150^{o} = \sin 30^{o} = \dfrac{1}{2}$
$\cos 150^{o}= - \cos 30^{o} = -\dfrac{\sqrt{3}}{2}$

b) $\cos \dfrac{\pi}{2} = \cos 90^{o} = 0$
$\sin \dfrac{\pi}{2} = \sin 90^{o} = 1$

c)$\cos \dfrac{3\pi}{2} = \cos 270^{o} = \cos 90^{o} = 0$
$\sin \dfrac{3\pi}{2} = \sin 270^{o} = -\sin 90^{o} = -1$

d)$\cos \pi = \cos 180^{o} = - \cos 0^{o} = -1$
$\sin \pi = \sin 180^{o} = \sin 0^{o} = 0$

e)$\cos 2\pi = \cos 360^{o} = \cos 0^{o} = 1$
$\sin 2\pi = \sin 360^{o} = \sin 0^{o} = 0$