Новое решение

Luisito правка от
правка #18638 позже →
@@ -0,0 +1,15 @@
+### Statement
+
+$13.3.4.$ [Insert the problem statement]
+
+### Solution
+
+For a thin len,\
+$\frac{1}{s}+\frac{1}{s'} = \frac{1/f}$\
+as the distance between the object and its actual image is minimal, $s = s'$,
+$\frac{2}{s} = \frac{1}{f}$\
+$s = 2f$
+
+#### Answer
+
+[Insert a concise answer or boxed result]