Discussion:  Roundtable 
Topic:  evaluating x^c 
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Subject:  evaluating x^c 
Author:  Bethany 
Date:  Sep 27 2004 
evaluated... as (x)^c or as (x^c). Using the TI83 there seems to be some
inconsistency between graphing and evaluating.
For instance, if I type in the expression 3.8^2.1 I get a response to be
16.502... Yet when I try to graph x^2.1 the graph is only defined for
positive x.
So it seems that the calculator when evaluating the expression takes 3.8^2.1
then negates it. But when it graphs it tries to evaluate (3.8)^2.1 which of
course _is_ undefined.
Also of interest to note is in MS Excel, typing that expression yields an
error.
So really, what do you as teachers expect that expression to evaluate to?
 
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