Tangent functions are very different sine and cosing functions.
When a table is made:
| 0 | 0 |
| 30 | 0.58 |
| 45 | 1 |
| 60 | 1.73 |
| 90 | undefined |
| 120 | -1.73 |
| 135 | -1 |
| 150 | -0.58 |
| 180 | 0 |
| 210 | 0.58 |
| 225 | 1 |
| 240 | 1.73 |
| 270 | undefined |
| 300 | -1.73 |
| 315 | -1 |
| 330 | -0.58 |
| 360 | 0 |
There are undefined in the tables. This means that there are no values in that spot; meaning asymptotes exist for this graph. Refer to Exponential Function if unsure.
As you can see from the image above, there are asymptotes on the left side of every tangent curve:
The right side of the curve does not have an asymptote — it is like any other quadratic/cubic (etc..) functions where the value continuously increases depending on the -values