One common way of expressing vectors is in terms of their components. for example, the x component of a⃗ , written ax, is equal to 2.5 (since that is its length along the x axis). likewise, the y component of a⃗ , written ay, is 3. you can express a vector in terms of its coordinates as follows: a⃗ =(ax, ay)=(2.5,3). what this means is that if the tail of the vector a⃗ is at the origin, then its tip is at the coordinates (x, y)=(2.5,3). when a problem in masteringphysics requires a vector answer in component form, the answer instructions will typically read something like "enter your answer as a pair of vector components, separated by a comma." in this case, you would enter your answer to the above scenario as 2.5,3. the surrounding parentheses should not be entered.