document.write( "Question 74896: Can anyone help me with this?\r
\n" ); document.write( "\n" ); document.write( "My problem is how to rationalize the denominator:\r
\n" ); document.write( "\n" ); document.write( "2/ sqrt[6] - sqrt[5]
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Algebra.Com's Answer #53818 by bucky(2189)\"\" \"About 
You can put this solution on YOUR website!
\"2%2F+%28sqrt%286%29+-+sqrt%285%29%29\"
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\n" ); document.write( "I'm going to assume that both the square root terms are in the denominator as shown above.
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\n" ); document.write( "You can rationalize the denominator through using the identity:
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\n" ); document.write( "\"%28a+%2B+b%29%2A%28a+-+b%29+=+a%5E2+-+b%5E2\"
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\n" ); document.write( "You can multiply out the left side of this identity just to convince yourself that the result
\n" ); document.write( "equals the right side.
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\n" ); document.write( "The denominator of the problem is of the form (a - b). Suppose that we multiply the entire
\n" ); document.write( "term of the problem by \"%28a+%2B+b%29%2F%28a+%2B+b%29\" which is equivalent to multiplying the term
\n" ); document.write( "in the problem by 1 since the numerator of this multiplier equals the denominator.
\n" ); document.write( "I used \"a\" and \"b\" so it might be easier to see what we're trying to do. Actually, we're
\n" ); document.write( "going to let:
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\n" ); document.write( "\"a+=+sqrt%286%29\" and \"b+=+sqrt%285%29\".
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\n" ); document.write( "So when we multiply the original problem by \"%28a+%2B+b%29%2F%28a+%2B+b%29\" we're actually going
\n" ); document.write( "to multiply it by \"%28sqrt%286%29%2Bsqrt%285%29%29%2F%28sqrt%286%29%2Bsqrt%285%29%29\".
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\n" ); document.write( "Let's do it:
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\n" ); document.write( "In accordance with the identity above, after multiplying the original denominator
\n" ); document.write( "of the problem by \"%28sqrt%286%29%2Bsqrt%285%29%29\" the new, rationalized denominator becomes
\n" ); document.write( "the difference between the squares of the two terms that were in the original denominator:
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\n" ); document.write( "But \"%28sqrt%286%29%29%5E2+=+6\" and \"%28sqrt%285%29%29%5E2+=+5\" so the new, rationalized denominator
\n" ); document.write( "just equals 6 - 5 or 1.
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\n" ); document.write( "Now all we have left to do is to work on the numerator.
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\n" ); document.write( "The numerator of the original problem is 2, but we multiplied it by \"%28sqrt%286%29%2Bsqrt%285%29%29\"
\n" ); document.write( "as part of the process associated with rationalizing the denominator. When we do this we get:
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\n" ); document.write( "\"2%2A%28sqrt%286%29%2Bsqrt%285%29%29+=+2%2Asqrt%286%29+%2B+2%2Asqrt%285%29\"
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\n" ); document.write( "That's the answer ... \"2%2Asqrt%286%29%2B2%2Asqrt%285%29\" because the new denominator that it is over
\n" ); document.write( "is just 1.
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\n" ); document.write( "Hope that after looking through this you'll be familiar with using the identity to rationalize
\n" ); document.write( "denominators. It will be useful to you when you work with complex numbers.
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