Laws of Reflection
First Law: The incident ray, reflected ray and normal all lie in the same plane.Second Law: Angle of incidence = Angle of reflection (∠i = ∠r)Mirror Formula
$$\frac{1}{v} + \frac{1}{u} = \frac{1}{f}$$
Sign Convention (New Cartesian)
Distances measured from pole of mirrorDistances in direction of incident light → positiveDistances opposite to incident light → negative