UnderGround Forums
 

AcademicGround >> Math Help ASAP Please


5/27/05 12:23 AM
Ignore | Quote | Vote Down | Vote Up
rushinbear
110 The total sum of your votes up and votes down Send Private Message Add Comment To Profile

Edited: 27-May-05
Member Since: 01/01/2001
Posts: 1803
 
I need some help on this problem. I thought I had it but then I ran into taking the square root of a negative number. Here it is and I need this thing when I wake up in ummm... 5 hours from now. I am doing this as a favor for my daughter for her friend. You have a circle with a diameter of 10 feet. Now envision this. You have a ruler that rises vertical from the bottom of the circle to the top of the circle which measures 10 feet up. Assume you fill the circle from the bottom (elevation is 0 feet) up to the very top which is 10 feet. At what elevation would the ruler be when the circle is at 90% filled area, 80% filled area, 70% filled area, and 60% filled area. As an easy example, when the circle is half filled, 50%, (shade the bottom half of the circle) the ruler would be up 5 feet. Thanks in advance....
5/27/05 11:47 AM
Ignore | Quote | Vote Down | Vote Up
jgibson
Send Private Message Add Comment To Profile

Edited: 27-May-05
Member Since: 04/30/2001
Posts: 5427
How did you end up taking a square root of a negative number?
5/27/05 9:34 PM
Ignore | Quote | Vote Down | Vote Up
Power Paw
Send Private Message Add Comment To Profile

Edited: 27-May-05 09:35 PM
Member Since: 01/01/2001
Posts: 2599
with an i or a j of course! 5i = sqrt(-25) polar coordinates
5/28/05 1:35 AM
Ignore | Quote | Vote Down | Vote Up
jgibson
Send Private Message Add Comment To Profile

Edited: 28-May-05
Member Since: 04/30/2001
Posts: 5438
Really Power Paw, what is this i and j you speak of? I don't think I have ever seen that in my EE courses.
5/28/05 1:50 AM
Ignore | Quote | Vote Down | Vote Up
Power Paw
Send Private Message Add Comment To Profile

Edited: 28-May-05
Member Since: 01/01/2001
Posts: 2600
hmm, i think there's a 90% chance that i'm being trolled but... i really think you have seen complex/imaginary numbers, ESPECIALLY since you're in electrical http://www.wtamu.edu/academic/anns/mps/math/mathlab/col_algebra/col_alg_tut12_complexnum.htm http://mathworld.wolfram.com/ComplexNumber.html http://mathforum.org/library/drmath/view/52613.html http://www.1728.com/compnum2.htm
5/28/05 1:56 AM
Ignore | Quote | Vote Down | Vote Up
Power Paw
Send Private Message Add Comment To Profile

Edited: 28-May-05
Member Since: 01/01/2001
Posts: 2601
http://mathforum.org/library/drmath/view/53879.html "*******************************************One of the most familiar examples where we use imaginary numbers, or "complex numbers" as they are sometimes called, is from electrical engineering***********************************, where imaginary numbers are used to keep track of the amplitude and phase of an electrical oscillation, such as an audio signal, or the electrical voltage and current that power electrical appliances. Check out the following Web pages on our site, which talk briefly about the electrical example as well as some others: Imaginary Numbers in Electricity http://mathforum.org/dr.math/problems/munoz7.31.98.html Real Life Applications of Imaginary Numbers http://mathforum.org/dr.math/problems/shah3.8.98.html Applications of Complex Numbers http://mathforum.org/dr.math/problems/stewart12.6.97.html Applications of Imaginary Numbers http://mathforum.org/dr.math/problems/zakrzewski10.14.97.html Imaginary Numbers http://mathforum.org/dr.math/problems/matt02.28.99.html Closely related to the electrical engineering example is the use of complex numbers in signal processing, which has applications to telecommunications (cellular phone), radar (which assists the navigation of airplanes), and even biology (in the analysis of firing events from neurons in the brain)."
5/28/05 8:42 PM
Ignore | Quote | Vote Down | Vote Up
jgibson
Send Private Message Add Comment To Profile

Edited: 28-May-05
Member Since: 04/30/2001
Posts: 5439
LOL. Sorry for the trolling.
5/31/05 5:08 PM
Ignore | Quote | Vote Down | Vote Up
iceman420
Send Private Message Add Comment To Profile

Edited: 31-May-05
Member Since: 06/30/2003
Posts: 2589
lol jgibson

Reply Post

You must log in to post a reply. Click here to login.