Question

for convex mirror... prove that.. f = r/2

Answer 1

let the radius be r
-radius is the distance from the centre of curvature to the pole
-focal length(f) is the distance from the focus to the pole
-focus is the midpoint of the radius
-so the radius is double the focus
-and hence f=r/2

hey bro please mark as brainliest

Answer 2

Answer:

Convex Mirror is a curved mirror where the reflecting surface propels towards the source of light.

Explanation:

To prove

f = r/2

f = focal length

r = radius

-radius (r) is the distance from the centre (C) of curvature to the pole

-focal length (f) is the distance from the focus (F) to the pole

-focus (F) is the midpoint of the radius (r)

∠ i = ∠ r ( according to law of reflection)

∠ i = ∠ a (corresponding angle)

therefore, ∠ a =∠ r

BF = FC (  triangle BFC is isosceles triangle)

BF ≅  PF

PF = FC = 1 / 2 PC

Focal length = 1 / 2 radius

hence, f = r/2

Learn more about convex mirror:

https://brainly.in/question/996707

https://brainly.in/question/7654757