What is an orthogonal matrix?

Orthogonal matrix refers to a matrix whose transpose is equal to the inverse matrix. Let A be an N-order square matrix and Aт be a transposed matrix. If AтA=E (identity matrix), A is called an orthogonal matrix.

Orthogonal matrix is a unitary matrix specialized by real numbers, so it always belongs to normal matrix. Orthogonal matrices are not necessarily real matrices. Real orthogonal matrix (that is, all elements in orthogonal matrix are real numbers) can be regarded as a special unitary matrix, but there are also complex orthogonal matrices, which are not unitary matrices.

Introduction to Teacher Li Yongle:

Li Yongle is a famous teacher in the middle school affiliated to Beijing Renmin University. He is proficient in physics and mathematics.

In 2009, Li Yongle graduated from Tsinghua University. He thinks he is not good at interpersonal communication. He wanted to find a job with a simple environment and regular life, applied for the middle school attached to the National People's Congress and became a physics teacher.

A series of popular science videos produced by Teacher Li Yongle and jointly produced by Watermelon Video and Popular Science China have spread all over the Internet, and CCTV News and People's Daily have forwarded them for praise.

The latest article "What is three-body? What is the relationship with the "Queqiao" satellite? In the video of Li Yongle's lecture on Lagrange Point, Li Yongle explained the reason and scientific principle behind the launch of China's lunar relay satellite "Queqiao" on May 2 1 to Lagrange Point in ten minutes.