Question

Tìm \(\alpha\) biết:

a) \(\sin\alpha=0\)

b) \(\sin\alpha=1\)

c) \(\sin\alpha=-1\)

d) \(\cos\alpha=0\)

e) \(\cos\alpha=1\)

f) \(\cos\alpha=-1\)

Answer 1

c, \(sin\alpha=-1\Leftrightarrow\alpha=-\dfrac{\pi}{2}+k2\pi\)

Answer 2

a, \(sin\alpha=0\Leftrightarrow\alpha=k\pi\)

Answer 3

b, \(sin\alpha=1\Leftrightarrow\alpha=\dfrac{\pi}{2}+k2\pi\)

Answer 4

d, \(cos\alpha=0\Leftrightarrow\alpha=\dfrac{\pi}{2}+k\pi\)

Answer 5

e, \(cos\alpha=1\Leftrightarrow\alpha=k2\pi\)

Answer 6

f, \(cos\alpha=-1\Leftrightarrow\alpha=\pi+k2\pi\)