# Dragging a line to fit an equation

Need help on how to do the following:

Below is the current shell of code I have. It makes an equation. What I want is for students to have to use the graph layer next to the note and drag a line on the graph to match the equation. How can I best do that?

``````r=randomGenerator()

m=numericValue("(-1)^\${r.int(0,1)}*\${r.int(2,6)}")
b=r.int(-8,8)

eq="y=\${m}x+b"

correct=??

co= when correct=1 "Correct! Good work" otherwise "Not there yet, keep working"

content: "
Given the following equation:

\${eq}

Match the line on the graph to represent the equation.

"
``````

Slide 34 on this activity is the slide in question

I’d use two points (myself I’d use sliders with a unit or half unit Step) that form a line. Then, check that slope and intercept are within desired tolerance.

That is exactly what I needed! Thank you!

Got a follow up if you have the time. I tried to expand upon this and make two lines but I am hitting a wall. Do you see what I am doing wrong? It is slide 35 on this link

Simple oversight. In your functions (f(x) and g(x)), you put x_a and x_b where it should just be x.

That did it. Thanks!

I am actually still having an error. Sometimes when I match one of the lines it will just say correct. Do you see where this may be coming from? I tried to set it up where either line could be placed where the given equation are. Do I need to somehow just set the top one for the purple line and the bottom one for the red line?

Slide 35

Played with it more on a duplicate slide (slide 36). I made it where the lines are specific to each equations. Red goes with the second one and purple with the top one. I also found that the c value shows up as 1 when the lines match in all cases except for the when the b is 0. Then it shows up as a zero. Everything else seems to be working from what I can tell.

Here’s my solution. I evaluated the difference of each function using a list of x values (function f-h, f-k, g-h, and g-k). I put everything in the Alternate Correction folder.

That’s perfect! Thanks so much!

It is reading both of these as correct, which is that initial problem I had as well. Any idea on this, or is it just one of those things you give them a warning about and just keep moving forwards?

Here is where it sees the error

Would a way to resolve this be something where you evaluate the target liens and the input line to see if they match outputs and that is an additional correctness check?

``````correct=graph.number(`C_{orrect}`)=0