Let A be an m×n matrix (that is, M rows and N columns), and the elements in row I and column J are a(i, J), that is, A=a(i, J).
The transpose of a is defined as such an n×m matrix b, which satisfies B=b(j, I), that is, A (I, J) = B (J, I) (the elements in row I and column J of b are elements in row J and column I of a), and A'=B is recorded. (Some secretaries are A? = b, where t is the superscript of a).
It is correct when a is a square matrix. Conclusion: If N-order square matrices A and B satisfy AB=E, then A and B are reversible, A- 1 = B, B- 1 = A, because A ta = E.
So a t = a-1+0.
Learn math skills
1, grab the classroom. Science study focuses on weekdays and is not suitable for surprise review. The most important thing to study on weekdays is to attend class for 45 minutes. Listen attentively and keep your thoughts close to the teacher. Finish homework with high quality. When writing homework, sometimes the same type of questions will be repeated. At this time, we should consciously check the speed and accuracy, and we can have a deeper thinking on such problems every time we finish.
2. For the wrong questions that can't be done: understand each step and think about why. For the wrong questions that have been miscalculated, if this happens frequently, then we should change the calculation methods and habits, such as learning to check the calculation twice to improve the accuracy.
The key is to think. The deeper you think, the more thoroughly you learn, and you can get high grades with a few questions. But this idea is not out of thin air, but based on the wrong question.