First, you can't simply write . It has to be tan of an angle, ex. , , etc. The trigonometric functions are there to determine the ratio between two sides based on an angle.
Yes you are right that and that . Both of them can only have values between -1 and 1.
For your question, construct a right angle triangle and label an angle . Since you know that , label the opposite side -2 (extending below the x-axis) and the adjacent side +3. Now find the hypotenuse and by the Pythagorean theorem and you should be able to find and .