Plotting Points and Lines
We have started by specifying the points A(2, 1) and E(7, 3). The next instruction 𝐴+𝑡(𝐸−𝐴) {0≤𝑡≤1}
draws the line from A to E. I decided to make it a dashed line as it will become the trajectory of a point.
The variable t is called a parameter. It takes all values between 0 and 1. At t=0, it gives us A, and at t=1, it gives us E. And the values of t between 0 and 1 trace out the line joining them.
Now you try: Plot points A(3, 7) and B(8,4) and draw a dashed line between them.
A Desmos protocol
It seems that t is the only variable you can use in this way. If you tried using s or T instead it wouldn’t work. That’s a decision Desmos made. Actually x and y can also be used in this way but they are already tied to the coordinate axes.
It seems that t is the only variable you can use in this way. If you tried using s or T instead it wouldn’t work. That’s a decision Desmos made. Actually x and y can also be used in this way but they are already tied to the coordinate axes.