A plane flying at 600 km/h on a straight horizontal course 5 km above the ground passes directly ovver an observer who is watching the plane through a telescope. How fast is the telescope rotating (a) at that moment? (b) one minute later?

Nvm, Trig problems. BORING.

It wasn't stated.

Not so much trig as calculus.

Haha, half trig half calc.
Well, precalc = in the middle.

This is one of those things that I can't quite remember how to do. It's in my calculus textbook, which is unfortunately at home.

It's a fun problem, though, I'll tell you that.

I tried using related rates, but I got different answers from the book. Mmm...maybe I'm not suppose to use it...

Oh yes, I agree. I've been staring at this problem for quite some hours and I still can't figure it out.

it is related rates.

theta= arctan(5t/600)

theta= arctan (t/120)

d theta / dt = 21600/ pi times (t^2 +14400)

d theta/ dt | t=0 = .477465 rad per hour

d theta/ dt | t= 1/60 = uh oh. same thing.


well, they're just... really close. it rounds to be the same thing.

i probably did this wrong...

oh crap. t is in the wrong place. let's try again.

theta= arctan (5/600t)

d theta/ dt= 21600/ pi times (14400 t^2 +1)

d theta/ dt | t=0 = 6875.45 rad/hour

d theta/ dt |t= 1/60 = 1375 rad/ hour

Mm, rates and extrema.

Hmm, you got the answer to b (0.4), but a is supposed to be 2 (in radians)

your askin the wrong person! hahaha sorry!!! good luck!

AP Calc BC exam was traumatizing. I don't want to go through this again...

*cowers*