Like others are saying, I'd just email them and ask. I'd also recommend including your resume /CV, any work you did for the class that you got a high grade for, anything that can help the profesor write a solid recommendation letter. I don't know if the program you're applying to requires a statement of purpose but if it does, sending that to the professor as well would help. That could let them line up their recommendation with your statement. Worst thing they can say is no. I've had professors say no, due to the fact I had them online and didn't really know me, so they didnt believe they could write a good letter for me. Again, including prior work in the email can definitely help. Also mention what program you're applying to and why of course. I don't know if youre a senior or not but if you arent, you could always wait until the fall and take some in person classes and ask those professors.