I'm in AP physics because I was really bored in acc physics, but I'm not actually in calculus, so I may ask you to explain basic concepts further if I have not yet had the chance to figure them out for myself. I was wondering about the equation for the moment of inertia of a uniform disc rotating about it's central axis. My book tells me that it's 1/2MR^2, but I attempted to arrive at that same equation myself and got MR^2, which is wrong-o. I've attempted several times trying different ways, but I think the problem isn't that I don't know how conceptually, it's that I haven't learned to think in calculus yet. If someone could explain to me how to do this that would be great . Thank you very much for your help. Also, I would like to know if mathematical symbols are built into this forum anywhere.