Square RootsDate: 08/19/2003 at 17:16:58 From: Emily Subject: Square Roots Why is a square root called a square root? Date: 08/20/2003 at 13:02:31 From: Doctor Ian Subject: Re: Square Roots Hi Emily, Suppose we have a square where we know each side has length 2: 2 +----+ | | 2 | | +----+ The area of the square is given by area = side * side = 2 * 2 = 4 Does that look familiar so far? Okay, now what if someone gives us a square, and tells us that the area is 9, and we want to know what the length of a side is? +----+ __ | | 9 = ? * ? ==> ? = \| 9 = 3 | | +----+ ? In this case, we want to know what number we can multiply by itself to get the area of the square, if we already know the area. We call this number the 'square root' of the area. In the same way, if we know the volume of a cube, but not the length of a side, +-----+ / /| / / | ___ +-----+ + 3| | | / 64 = ? * ? * ? ==> ? = \| 64 = 4 | |/ +-----+ ? we take the 'cube root' of the volume to find the length of a side. Does this help? - Doctor Ian, The Math Forum http://mathforum.org/dr.math/ |
Search the Dr. Math Library: |
[Privacy Policy] [Terms of Use]
Ask Dr. Math^{TM}
© 1994-2013 The Math Forum
http://mathforum.org/dr.math/