sebuah benda diletakkan 15 cm di depan cermin cembung. jika kelengkungan cermin cembung 60 cm barapaka jarak bayangan

s = 15 cm
f = 60 cm
1/f = 1/s + 1/s'
1/s' = 1/f - 1/s
1/s' = 1/60 - 1/15
1/s' = (1-4)/60
1/s' = (-3)/60 = (-1)/20
s' = -20 cm

semoga membantu (y)