## 2019年10月21日月曜日

### 数学 - 円の中にひそむ関数 - 三角関数 - 一般角と三角関数 - 正弦・余弦 - 全ての実数

1. $\mathrm{sin}\frac{3}{4}\pi =\frac{1}{\sqrt{2}}$

2. $\mathrm{cos}\frac{3}{4}\pi =-\frac{1}{\sqrt{2}}$

3. $\mathrm{sin}\frac{2}{3}\pi =\frac{\sqrt{3}}{2}$

4. $\mathrm{cos}\frac{2}{3}\pi =-\frac{1}{2}$

5. $\mathrm{sin}\frac{4}{3}\pi =-\frac{\sqrt{3}}{2}$

6. $\mathrm{cos}\frac{4}{3}\pi =-\frac{1}{2}$

7. $\mathrm{sin}\frac{11}{6}\pi =-\frac{1}{2}$

8. $\mathrm{cos}\frac{11}{6}\pi =\frac{\sqrt{3}}{2}$

9. $\mathrm{sin}\left(\frac{5}{6}\pi +4\pi \right)=\frac{1}{2}$

10. $\mathrm{cos}\left(\frac{\pi }{3}-8\pi \right)=\frac{1}{2}$

11. $\begin{array}{l}\mathrm{sin}\left(-\frac{11}{4}\pi \right)\\ =\mathrm{sin}\left(-\frac{3}{4}\pi \right)\\ =-\frac{1}{\sqrt{2}}\end{array}$

12. $\mathrm{cos}\left(-\frac{11}{4}\pi \right)=-\frac{1}{\sqrt{2}}$

13. $\begin{array}{l}\mathrm{sin}\left(-\frac{19}{3}\pi \right)\\ =\mathrm{sin}\left(-\frac{1}{3}\pi \right)\\ =-\frac{\sqrt{3}}{2}\end{array}$

14. $\mathrm{cos}\left(-\frac{19}{3}\pi \right)=\frac{1}{2}$

15. $\begin{array}{l}\mathrm{sin}\left(501\pi \right)\\ =\mathrm{sin}\pi \\ =0\end{array}$

16. $\mathrm{cos}\left(501\pi \right)=-1$