| NULL | $0^{o}$ | $30^{o}$ | $45^{o} $ | $60^{o}$ | $90^{o}$ |
| $\sin x$ | $0$ | $\frac{1}{2}$ | $\frac{\sqrt{2}}{2}$ | $\frac{\sqrt{3}}{2}$ | $1$ |
| $\cos x$ | $1$ | $\frac{\sqrt{3}}{2}$ | $\frac{\sqrt{2}}{2}$ | $\frac{1}{2}$ | $0$ |
| $\tan x$ | $0$ | $\frac{\sqrt{3}}{3}$ | $1$ | $\sqrt{3}$ | 不存在 |
| $\cot x$ | 不存在 | $\sqrt{3}$ | $1$ | $\frac{\sqrt{3}}{3}$ | $0$ |
EOF