Problem 74 Clock Hands (Possible error in example)
Back to Problem Solutions forum
Hi everyone,
I started to work on this problem and it looks like im stuck forever. I just cant understand how does system calculate cos and sin.
In given example there is a result that looks strange to me. I mean how x-coordinate of hour hand can be 4.20444504 at 9? If we imagine clocks and take a look at the hour hand at 9 o'clock it will be parallel to X-axis hence, it's x-coordinate has to be hand length substracted from center of circle ( 10 - 6 = 4 ) and it's y-coordinate has to be 10 but in the example they are 4.20444504 and 11.55291427
input data: 3 12:00 15:00 9:30
answer: WTF? WTF?
10.0 16.0 10.0 19.0 16.0 10.0 10.0 19.0 4.20444504 11.55291427 10.0 1.0
Please correct me if im wrong, but it looks like this problem is unsolvable
Hi there, and thanks for your message!
At first you almost caught me :) But seems no, not a bug...
If we imagine clocks and take a look at the hour hand at 9 o'clock it will be parallel to X-axis hence?
Right. It is parallel at 9:00, but not in 9:30, since the hands rotate smoothly and 30 minutes after 9:00
the hour hand moves forward 7.5 degrees...
(by the way it seems the picture in the problem shows exactly that position)
Hi Rodion, thx for fast answer.
Oh, guess it was a bug in my head. Maybe i should get used to these type of clock instead of digital ones.
Hm-m-m... Your point is good... I have just understood that such a problem becomes, well, somewhat outdated... Because people use digital clock far more often nowadays (including me). Valuable hint, thanks! :)
Let's add small clarification to the problem then... Thanks once more!