document.write( "Question 1134898: Why is it NOT necessary for two radical expressions have the same index if they are to be multiplied? Provide your own example including correct answer. \n" ); document.write( "
Algebra.Com's Answer #752399 by MathLover1(20849)\"\" \"About 
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\n" ); document.write( "One way to look at this is to take two radicals: \"sqrt%28a%29\" and \"root%283%2Cb%29\", which differing indices. \r
\n" ); document.write( "\n" ); document.write( "But we can introduce the \"LCM+\"of \"2\" and \"3\" which is \"6\" and write
\n" ); document.write( "\"sqrt%28a%29=root%286%2Ca%5E3%29\" and \"root%283%2Cb%29=root%286%2Cb%5E2%29\" where the number \"2\" and \"3\" is the \"index\".\r
\n" ); document.write( "\n" ); document.write( "This introduces a \"common\" radical - \"6\"th root.\r
\n" ); document.write( "\n" ); document.write( " Now we multiply under the \"same\"\"+index\": \r
\n" ); document.write( "\n" ); document.write( ".\r
\n" ); document.write( "\n" ); document.write( "So in the general case we need the \"LCM\" of the indices as the\"+common\" radical and then we use the power indices under the common radical. \r
\n" ); document.write( "\n" ); document.write( "So it is \"not\"\"+necessary\" for \"2\" radical expressions to have the \"same\"\"+index\" in order to \"multiply\" them.\r
\n" ); document.write( "\n" ); document.write( "NUMERICAL EXAMPLE: \r
\n" ); document.write( "\n" ); document.write( "\"sqrt%28121%29\" and \"root%283%2C27%29\"\r
\n" ); document.write( "\n" ); document.write( "\"sqrt%28121%29=11\" and \"root%283%2C27%29=3\"\r
\n" ); document.write( "\n" ); document.write( " We know the answer is \"11%2A3=33\". \r
\n" ); document.write( "\n" ); document.write( "But let's see if we get the same result by putting \"a=121\" and\"+b=27\" in the formula above.\r
\n" ); document.write( "\n" ); document.write( " \"sqrt%28121%29%2Aroot%283%2C27%29\"\r
\n" ); document.write( "\n" ); document.write( "=\"root%286%2C%2811%5E2%29%5E3%29%2Aroot%286%2C%283%5E3%29%5E2%29\"\r
\n" ); document.write( "\n" ); document.write( "=\"root%286%2C177561%2A729%29%7D%7D%0D%0A%0D%0A=%7B%7B%7B11%2A3\"\r
\n" ); document.write( "\n" ); document.write( "=\"33\"\r
\n" ); document.write( "\n" ); document.write( " So the formula works.\r
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