Graphing y = (-2)^x
Date: 05/27/2005 at 03:32:18 From: John Subject: graphing (-2)^x I wanted to graph (-2)^x (or any negative number to the X power) but my math teacher could not provide me with a solution. How would I graph this? Some points work and some don't. I do know that if I plug in whole numbers it will work, but if I plug in decimals and fractions I run into the problem of square roots of negative numbers.
Date: 05/27/2005 at 22:14:29 From: Doctor Vogler Subject: Re: graphing (-2)^x Hi John, Thanks for writing to Dr. Math. The trouble is that a^b is not clearly defined when a is negative. It only has meaning when b is rational, and then only when the denominator of b is odd. So your function is only defined at certain rational points, and otherwise is full of holes. But the graph will look like two dotted lines, one of which is y = 2^x and the other is y = -(2^x) because (-2)^x will always equal one of the above two values when it is meaningful at all. See also Base of an Exponential Function http://mathforum.org/library/drmath/view/55604.html If you have any questions about this or need more help, please write back and show me what you have been able to do, and I will try to offer further suggestions. - Doctor Vogler, The Math Forum http://mathforum.org/dr.math/
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