A vector may change when we :

Options

A. Rotate the coordinate axes
B. Slide the vector without changing orientantion
C. rotate the vector
D. all of the above

Answer

To solve the question "A vector may change when we:", we need to analyze the conditions under which a vector can change.

### Step-by-Step Solution:

1. **Understanding Vectors**: A vector is defined by both its magnitude (length) and direction. Therefore, a change in either of these components will result in a change in the vector itself.

2. **Magnitude Change**: If we increase or decrease the length of the vector, we are changing its magnitude. For example, if a vector originally has a length of 5 units and we change it to 10 units, the vector has changed.

3. **Direction Change**: If we rotate the vector or change its angle with respect to a reference axis, we are changing its direction. For instance, if a vector points to the right and we rotate it to point upwards, the vector has changed.

4. **Sliding the Vector**: It is important to note that sliding a vector along a plane without changing its orientation does not change the vector. The vector remains the same as long as its magnitude and direction are unchanged.

5. **Conclusion**: Therefore, a vector may change when we either change its magnitude or change its direction.

### Final Answer:
A vector may change when we:
- Change its magnitude
- Change its direction