Jawabanmu

2014-05-12T15:46:23+07:00
F = 4 cm
1/4 - 1/12 = 2/12 -> bayangan = 6 cm
perbesaran, bayangan/benda =  6/12 = 1/2 (diperkeciI)
2014-05-12T17:03:21+07:00
Titik fokus (F) = 1/2 x 8 = 4
⇒ 1/F = 1/s + 1/s'
    1/4 = 1/s + 1/12
    1/s = 1/4 - 1/12
    1/s = 3/12 - 1/12
    s = 6
⇒ M = -s'/s
    M = -12/6
    M = -2
perbesarannya = 2
sifat bayangannya nyata, terbalik, dan diperbesar