Then every time the minute hand turns, the hour hand turns 6 * 5 = 30, which means 360:30= 12: 1.
That is, minute hand rotation 12 and clockwise rotation 1.
Because Xiaoming arrived at the library at 10/2 and Xiaoli was already reading, the time must be before 12:10 and after 1 1:30.
Moreover, at the position of 12, the hour hand and the minute hand just coincide with the number 12 on the dial, that is, 12-1=1,so we can know that there are two situations, or the minute hand and the number/kloc-. Exactly 12-1 =1,or the minute hand exceeds the number 12,12, so the hour hand exceeds1,which is exactly12-.
Because 6 is a small cell, 12=6*2.
So we know that the time is 1 1:58 or 12:02.
If the formula is listed: set the time as x, then there are
(180-6 * 2.5)-6x+(1 1 2) * 6x = plus or minus11.
Get 28 or 32
180-6*2.5 is the starting angle of 1 1:30.
-6x per minute, minute hand reduced by 6.
(112) * 6x hour hand increases every minute (112) * 6.
+1 1, there are two cases, one is to directly form the angle of 1 1, which is positive, and the other is to reach 0 first, and then form the angle of 1 1, which is negative. (The positive and negative angles here are not really positive and negative, but are similar to the concept of quadrants. If you haven't learned it, then honestly calculate the second 1 1. )