Question

in case of concave mirror if 10cm and 40cm are the distance of object and it's image respectively from the focus then the focal length of the he mirror is​

Answer 1

Explanation:

Let f be focal length

u=−(x1+f) and v=−(x2+f)

From mirror formula, v1+u1=f1

x2+f−1+x1+f−1=f−1

(x1+f)(x2+f)x1+x2+2f=f1

(x1+x2+2f)f=(x1+f)(x2+f)

(x1+x2)f+2f2=x1