Oblicz ogniskowa soczewek (f) Soczewka 1- X=5,6 Y=6,3 S2- X=6,3 Y=8,3 S3- X=12,8 Y=10,6 Wszystko w centymetrach

soczewka 1 x = 5,6 cm y = 6,3 cm f = ? 1/f = 1/x + 1/y 1/f = 1/ 56/10 + 1/ 63/10 1/f  = 10/56 + 10/63 1/f = 10·63/56·63 + 10·56/56·63 1/f = 630/3528 + 560/3528 1/f = 1190/3528 f = 3528/1190 f = 2,9 cm   soczewka 2 x = 6,3 cm = 63/10 cm y = 8,3 cm = 83/10 f = ? 1/f = 1/x + 1/y 1/f = 1/ 63/10 + 1/ 83/10 1/f = 10/63 + 10/83 1/f = 83·10/63·83 + 63·10/63·83 1/f = 830/5229 + 630/5229 1/f = 1460/5229 f = 5229/1460 f = 3,5 cm   Soczewka 3 x = 12,8 cm = 128/10 cm y = 10,6 cm = 106/10 cm f = ? 1/f = 1/x + 1/y 1/f = 1/ 128/10  +  1/ 106/10 1/f = 10/128 + 10/106 1/f = 10·106/128·106  + 10·128/128·106 1/f = 1060/13568 + 1280/13568 1/f = 2340/13568 f = 13568/2340 f = 5,8 cm