Mathematics
Grade9
Easy
Question
Identity matrix gives the initial polygon matrix when multiplied with rotation matrix of _________.
- 90°
- 180°
- 270°
- 360°
Hint:
a rotation of 360n is same as initial .
The correct answer is: 360°
A rotation of 360° returns the figure to its original position. Multiplying by the matrix that represents this rotation gives you the polygon matrix you started with, so it is called the identity matrix.
so , when you rotate by a multiple of 360 you will always get same identity matrix .