# Hide submit button after student inputs correct answer

**URL:** https://cl.desmos.com/t/hide-submit-button-after-student-inputs-correct-answer/1525
**Category:** Questions
**Created:** [September 17, 2020, 4:55pm UTC](https://cl.desmos.com/t/hide-submit-button-after-student-inputs-correct-answer/1525 "2020-09-17T16:55:37Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Z.Shiner](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/z.shiner/32/1144_2.png) [@Z.Shiner](https://cl.desmos.com/u/Z.Shiner)
#### Post date: [September 17, 2020, 4:55pm UTC](https://cl.desmos.com/t/hide-submit-button-after-student-inputs-correct-answer/1525/1 "2020-09-17T16:55:37Z")

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Hi!

I’m working on a Desmos tool to assess students’ ability to differentiate functions. [Here](https://t.co/8shiseLkVu?amp=1) is what I have so far. I’m trying to set it so that when a student gets a correct answer they can no longer submit their work. I imagine it would utilize the “showSubmitButton” sink, but I’m not sure how to activate it + check for correctness only after students press the button. Any advice?

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### Author: ![Daniel\_Grubbs](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/daniel_grubbs/32/719_2.png) [@Daniel\_Grubbs](https://cl.desmos.com/u/Daniel_Grubbs)
#### Post date: [September 17, 2020, 6:16pm UTC](https://cl.desmos.com/t/hide-submit-button-after-student-inputs-correct-answer/1525/2 "2020-09-17T18:16:24Z")

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I’m getting a server error for your link. Use the link from “Share Activity” not the URL from the address bar, but probably yes the `showSubmitButton` sink. You can use a `when-otherwise` or whatever condition is needed for true. Say you made a Boolean, `check`, to see if the student is correct or not:

`showSubmitButton: when check false otherwise true`

OR

`showSubmitButton: not(check)`

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<div class="post-metadata">

### Author: ![Z.Shiner](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/z.shiner/32/1144_2.png) [@Z.Shiner](https://cl.desmos.com/u/Z.Shiner)
#### Post date: [September 17, 2020, 11:15pm UTC](https://cl.desmos.com/t/hide-submit-button-after-student-inputs-correct-answer/1525/3 "2020-09-17T23:15:22Z")

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Thanks for the help. I think the server error was on the Desmos side from when [teacher.desmos.com](http://teacher.desmos.com) was down earlier. I ended up using:

> hidden: rightAnswer and this.submitted

Which also has the effect of not allowing students to adjust their answer after submitting.

I’m going to have to remember that though - it’ll definitely be helpful in other places.