# Graphs of acceleration, velocity, position

im confused with finding the max velocity , acceleration, and position.
Usually in these types of problems I'm given a function, and an interval and have to find the max acceleration or velocity.

Sometimes a negative number comes up which is greater in magnitude than the other numbers, and that is the answer. I don't get why. Can someone please explain?
Sorry if I'm being vague, i can't really explain it too well.

mfb
Mentor
I don't see what would be special about a negative number. Negative and positive are arbitrary anyway, you could measure in the other direction and all signs would get swapped.

DennisN
2020 Award
Like mfb said, it's about directions.

Consider a horizontal line (which is 1-dimensional) and define a particular position, (i.e. point) as (0): all the positions (points) to the left of (0) will be negative, and all the positions (points) to the right of (0) will be positive.

• A negative position will mean a position to the left of (0), a positive position will mean a position to the right of (0).
• A negative velocity will mean motion to the left along the line, a positive velocity will mean motion to the right.
• A negative acceleration will mean acceleration to the left along the line, a positive acceleration will mean acceleration to the right.
The same applies for 2-dimensional and 3-dimensional space too. Velocity and acceleration (and forces etc.) are vector quantities. Vectors have both magnitude and direction. See Euclidean vector. 