Correct answers are a) and d)
[tex]\alpha=- \frac{\pi}{4}
[/tex]
Coterminal angles: [tex]\alpha+k\pi,\,k\in Z[/tex]
[tex]- \frac{\pi}{4}+2\pi=- \frac{\pi}{4}+ \frac{8\pi}{4} = \frac{7\pi}{4}
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\\- \frac{\pi}{4}-2\pi=- \frac{\pi}{4}- \frac{8\pi}{4} = -\frac{9\pi}{4}[/tex]
