I just learnt vectors as a prerequisite to learning mechanics and I have a few doubts:- 1) For 1D motion, there are only two possible directions, so they can be represented by just a + or - sign, where you have to define which direction is positive and which is negative. But for 2D how do you represent the direction of a vector? Clearly, just + or - will not do the job. I thought of a few ways to completely describe the direction of a vector in 2D:- Using words such as North, North East, left, right etc. but this isn't precise and will not suffice for vectors that aren't in the 8 simple directions. Defining a line like an x-axis, and using the angle the vector makes with the defined line to describe it's direction. Defining x and y axes and then resolving the vectors along the axes. So the vector will be expressed as the sum of an x-component and a y-component with + and - signs representing the directions of the components along their respective axis. So what method do people use to describe direction of vectors in 2D? 2) When we are drawing displacement-time graphs, along the displacement axis there is only + and -. So does this mean that we can draw displacement-time graphs for motion in 1D?