Practice question

**Mirror formula** 1/f = 1/v + 1/u governs spherical mirrors, f = R/2, R radius of curvature (m), u object distance (m), v image distance (m), sign convention: distances in front of mirror negative for real is convention but magnitude used, magnification m = -v/u, concave forms real inverted when object beyond F, virtual erect within F. Object distance: u = -6 cm (virtual object), f = 12 cm . Lens formula: (1/v) - (1/-6) = (1/12) ⇒ (1/v) + (1/6) = (1/12) . (1/v) = (1/12) - (1/6) = (1 - 2/12) = (-1/12) . v = -12 cm (12 cm to the left).