2. Calculate the included angle between two vectors (related to the product of quantities).

3. Use the addition and subtraction of several vectors to represent a vector. (It seems that high school is two-dimensional and three-dimensional)

4. Modulus of the vector.

5. The relationship between vectors (* * * straight line, vertical, equal ...) and the relationship between coordinates.

Almost. It is not difficult to remember this when reviewing in senior three.