Homework help!

Post by **CronoTriggerfan** » Mon May 14, 2007 4:18 pm

I was home sick today, and I'm desperately trying to catch up on my schoolwork. I've done everything so far with no trouble, but I took HORRIBLE notes on Friday in math, and am pretty damn lost on how to do some of this stuff. Could anyone lend a helping hand, like work out a few example problems and explain? I do NOT want this done for me, I just want to understand. Thanks!

CTFan

OAtH_OS · Post by **OAtH_OS** » Mon May 14, 2007 4:52 pm

1. 65/360=65/360=18.15/32(pi)=145.21/256(pi)

just put the first 2 steps for each one (but replace 65 with the degree of that problem).
to get the 3rd step:
multiply the radius by 2(pi) to get 32 (pi) as the denominator. to get the numerator, 32 * (pi) = 100.5396.... then /360= .2792.... then .279.... * 65 = 18.15

4th step:
radius to the second *(pi) ---> 256(pi) for denominator, and for numerator repeat the thing in step 3 but instead of 32, use 256.

post here when your done with 1-4.

Post by **bicostp** » Mon May 14, 2007 5:02 pm

WARNING: It's been a while since I've done this.

The length of the arc isn't too complicated, but you're going to have to use radians.

<img src="http://img509.imageshack.us/img509/3372 ... etahu4.png">

S is the length of the arc, r is the radius, and theta (the 0 with a little squiggle in it, if you never saw it before) is the measure of the angle in radians. (You can't use this formula when the angle is expressed in degrees.)

Let's say for this example we have a circle with a 10 inch radius and the angle is 120 degrees. Start by converting 120 degrees to X radians. Multiply 120 by π/180. (Pi over 180; don't divide 3.14159... by 180 yet.) It's easiest if you simplify as much as possible and still have whole numbers.

<img src="http://img525.imageshack.us/img525/7489 ... ifyjp3.png">

Now we can start to use the equation above. We know that the radius is 10 and the angle in radians is 2π/3 . All that's left to do is plug and grind.

<img src="http://img525.imageshack.us/img525/3416 ... werrm9.png">

The final answer is approximately 20.94 inches. (It's not exact because we didn't use all eleventy-billion digits of Pi.)

Hope you can read my chicken-scratch.

That should get you through #7.

Zzebotes13 · Post by **Zzebotes13** » Mon May 14, 2007 6:58 pm

i just had a test on this, and bicotps way s much easier once you get used to using radians

Post by **CronoTriggerfan** » Mon May 14, 2007 8:52 pm

I can't thank you guys enough for all your help!

I'm finishing up the worksheet now! Thanks a ton for taking the time to work this stuff out, I really appreciate it.

CTFan