Rationalize Denominators of Radical Expressions help (one question)
- Thread starter BlueIvy
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- Feb 4, 2004
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That looks to me to be a typo.
If you're not sure, do the simplification (take the "minus" through the parentheses, group "like" terms, etc), and see what you get!
D
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1. Where did the "y" value go and how did it get replaced with "x". Sorry, I don't see how that happened.Hello, please see image below and the areas boxed in "red".
1. Where did the "y" value go and how did it get replaced with "x". Sorry, I don't see how that happened.
2. Did the two bottom y2 and +y2 values cancel each other out?
That is a mistake! "y" should have remained "y".
2. Did the two bottom -y2 and +y2 values cancel each other out? Yes
When in doubt
to check for a possible error and avoiding trying to make sense of something that doesn't make sense, try substituting in values for x and y.
let x = 3, y = 4 for example. Does evaluating the first and last expression give the same result? No. Not proof positive but a good indication that you might spend your time more profitably elsewhere. Note, if ambitious you could substitute x = 3, y = 4 all the way down the chain to find the source of the error. This is a good technique for finding errors in ones own sequence of calculations if the result is incorrect.
Hello, please see image below and the areas boxed in "red".
1. Where did the "y" value go and how did it get replaced with "x". Sorry, I don't see how that happened.
2. Did the two bottom y2 and +y2 values cancel each other out?
to check for a possible error and avoiding trying to make sense of something that doesn't make sense, try substituting in values for x and y.
let x = 3, y = 4 for example. Does evaluating the first and last expression give the same result? No. Not proof positive but a good indication that you might spend your time more profitably elsewhere. Note, if ambitious you could substitute x = 3, y = 4 all the way down the chain to find the source of the error. This is a good technique for finding errors in ones own sequence of calculations if the result is incorrect.