Step-by-step explanation: To solve this question first we need to know that the terminal point pair (little red point in the image) represented by the coordinates represent the (cosine, sine) as shown bellow
We also need to understand that the "tan" formula can be expressed as follows

So all we need to do is to substitute and calculate.
Step 1: Let's substitute the values and calculate as follows

Step 2: Now let's rationalize the result as follows

Final answer: So the final answer is

.