ELI5: Explain Like I'm 5

Trigonometric functions of matrices

Trigonometric functions of matrices are mathematical equations that involve matrices. Matrices are like grids with numbers in them and they can help us work out lots of different kinds of problems. Trigonometric functions are equations involving angles, such as sine and cosine. When you use these functions with matrices, you use the angles in a matrix along with the sine and cosine equations to work out some kind of answer.