#### You are provided with a convex mirror. To determine its focal length using the parallax method, follow these steps: 1. Set up the convex mirror on a stand and place an object at a distance of 60 cm in front of the mirror. 2. Observe the object through the convex mirror while moving your head from side to side, noting the apparent shift in the position of the object.3. Measure the distance between your eyes and the mirror to be 25 cm. Given: • Distance between the object and the convex mirror, Do = 60 cm • Apparent shift of the object, d = 6 cm • Distance between your eyes and the convex mirror, De = 25 cmAssumptions: • The convex mirror is properly aligned and positioned.Option: 1 -30.2 cmOption: 2 -33.7 cmOption: 3 -37.5 cmOption: 4 -29.1 cm

Apply the parallax method formula to calculate the focal  length (f) of the
convex mirror:

$f= \frac{D_{o}. D_{e}}{D_{o}-D_{e}}$
Substitute the given values into the formula:

$f= \frac{60 cm. 25 cm}{60 cm-25 cm}$

Calculate the focal length:

f = −37.5 cm
The focal length of the convex mirror, determined using the parallax method, is approximately −37.5 cm.