 Here, I have a problem with randomized numbers. In my case, this ring constant, the total energy and the initial position are randomized. Now, I want to randomize a bit more. In this case, here, I made it that it's based on a cosine function. So I want to change this as based on a sine function. So how do I do this? Let me go back in the code. So the first time I'm actually using the cosine function is down here, where I calculate my phase constant. So instead of cosine, I want to use sine as an option. So what I do is I'm going to add two possible cases. So I'm going to do here case shows, and I make a note to myself. One is cosine, two is sine. Now, I'm going to do a if. If case is one, then in this case, this arc cosine, else we're going to be using arc sine. And now we know I'm not going to need that one here. So now my answer will calculate based on arc cosine one case and based on sine in the other case. Now, how do I update this in the question? So here, it appears down here, based on. So here, I'm going to just make my text finish here. And then I do again my if branching. If case is one, my question, I'm going to append the text. This question is question two, and I'm just going to add what I had before. Cosine, and if it is case two, then I'm going to display sine here. And now let's see if that worked. So something is wrong. What did I do wrong? I did something, sine, cos. Arc sine. Okay, so blah, blah, blah, blah. Now it did it with sine, right? So it should technically work. If I want to see what happens with sine, so amplitude of the system, actually I can show the correct answers. So here we have the amplitude of the system. That sounds about right. So in my case, so now in my case, it is planted with sine. If I want to check the other one, all I have to do is I actually have to temporarily overwrite here. My case, so if case equals to one, then it should show me the one with cosine and will calculate the answer based on cosine. It doesn't change anything for A in this case. If I'm going on two, then it will calculate me the answer in sine. So before I save this and make it go live, I of course have to remove my random overwrite. And let's do this again. So now I'm having sine or at random some students will get cosine. Now if you're a physics teacher, you know that there is now another problem with this, which is one of the two is much easier than the other. So I will have to make some adjustments as well in the question, just to make them equally challenging. And yeah, if you're a student, think about what I'm talking here about. I'm not going to tell you that's not the point of this video.