3.4 Ray tracing

1.1 Few general points of geometrical optics
1.2 Object and image

2.1 Laws of reflection of light
2.2 Reflection by a plane mirror

3.1 Paraxial approximation
3.2 Spherical mirrors
3.3 Sign convention
3.4 Ray tracing
3.5 Image formation by concave mirror
3.6 Image formation by convex mirror

5.1 Lateral magnification
5.2 Longitudinal magnification
5.3 Superficial magnification

6.1 Graph between $\left( {\frac{1}{v}} \right)$ and $\left( {\frac{1}{u}} \right)$

In geometrical optics, to locate the image of an object, tracing of a ray as it reflects from a mirror is very important.

Ray 1: A ray through the centre of curvature which strikes the mirror is normally reflected back along the same path.

Ray 2: A ray parallel to principal axis after reflection either actually passes through the principal focus $F$ or appears to diverge from it.

Ray 3: A ray passing through the principal focus $F$ or a ray which appears to converge at $F$ is reflected parallel to the principal axis.

Ray 4: A ray striking at pole $P$ is reflected symmetrically back in the opposite side.