It’s okay! Try to be as relaxed as possible when answering questions. This will strengthen the teacher’s good impression of you. Even if you don’t answer the question, you will be punished by standing still or you will be criticized by the teacher, you can still do it after class. Go ask the teacher how to solve this question, and your attitude should be sincere and serious. Besides, the teacher is strict with you for your own good. Don't be angry with the teacher!