# How do I write a code for "correct equation"

I want my students to graph a sin function with an amplitude of 3 and a midline at y=2

This is a strategy that will work for any function and it relies on the use of the calculator. Here’s the functions you can use in the calculator:

In the graph component, use this CL:

``````function(`f`): simpleFunction(input.latex)
``````

I’m not sure if you’re just looking for a dashboard display or some other feedback, but when the C_{heck} variable in the graph equals 1, the graph is correct.

I want the students to check: y=4sinx/3pi to know they have the right equation

Take the calculator screen I shared earlier and copy the URL. Open the graph on the activity you’ve shared and paste the URL into a line with an empty expression. In the folder that says “Correct Function,” enter the correct function. The other code I shared still applies. If you can’t get that to work, please share the activity as it’s easier to make adjustments that way.

I’ve found that this does cause issues if you have an undefined output (e.g. using tanx instead of sinx and your list in increments of pi/4). Here’s how I changed your `C_{heck}` to avoid undefined values breaking it.

Note: I used the square root function as an example. C_{heck2}=0 but C_{heck} is okay.

Thanks for pointing that out. That thought didn’t cross my mind!

Here’s the graph I’d use for Slide 2. I’m guessing there’s a way to do it with pattern checking, but I’m not there yet.

For dashboard correctness, use this in the input:

``````midline= Sketch6.number(`m_{id}`)=2
amplitude= Sketch6.number(`a_{mp}`)=3

correct: midline and amplitude and this.submitted
``````

If you just wanted the equation `f(x)=3sin(x)+2` you could just change g(x) in my AutoCheck Functions graph to this equation. (My example in this post will also allow horizontal translations.)

You might one to explore the activity I made. Slide 20 was fun to program. I belive you might want to reuse some of my slides