একটি অবতল দর্পণের জন্য কার্তেসীয় চিহ্ন প্রথা

graph TB A[Cartesian Sign Convention for a Concave Mirror] --> B[Origin] B --> C[The pole of the mirror] A --> D[Direction] D --> E[The direction of incident light at the mirror] A --> F[Signs] F --> G["All distances measured to the right of the origin
(along +x-axis) are taken as positive"] F --> H["All distances measured to the left of the origin
(along -x-axis) are taken as negative"] F --> I[The distances measured in the direction
of incident light are positive] F --> J[The distances measured against the direction
of incident light are negative] F --> K[The height above the principal axis
is taken as positive] F --> L[The height below the principal axis
is taken as negative]