The math help thread

Well, here's what I did.


<---- ERROR!!!!!!


at one o'clock, the angle between the hands is pi/6 rads
cos(A) = sqrt(3)/2
sin(A) = 1/2

dA/dt = 2pi radians in 12 hours = pi/6 rads/h<---- ERROR!!!!!!





He had his on a test and had it marked right, so if our answers don't match, mine must be wrong, and if so, I'm not sure where I went wrong in my steps.

sqrt(4) = 2, not 4.

If angle A is the angle between the minute hand and the hour hand, dA/dt is NOT 2*π radians per 12 hours. Rather, you should have found the difference dA/dt minute hand - dA/dt hour hand = net dA/dt. That's 2*π radians per hour - 2*π radians per 12 hours, or 2π/3600 rad/second - 2π/43200 = 11π/21600. Your real dA/dt was really -11π/21600 in/sec

And why didn't I think of Law of Cosines >.< lmao