document.write( "Question 1031765: f(x)=2x^2-1
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Algebra.Com's Answer #646427 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
(a)\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29+=+%282x%5E2-1%29%2F%28x%5E2%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%285%29+=+%282%285%29%5E2-1%29%2F%28%285%29%5E2%29\" Replace EVERY copy of x with 5\r
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\n" ); document.write( "\n" ); document.write( "\"f%285%29+=+%282%2825%29-1%29%2F%2825%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%285%29+=+%2850-1%29%2F%2825%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%285%29+=+49%2F25\"\r
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\n" ); document.write( "\n" ); document.write( "(b)\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29+=+%282x%5E2-1%29%2F%28x%5E2%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-5%29+=+%282%28-5%29%5E2-1%29%2F%28%28-5%29%5E2%29\" Replace EVERY copy of x with -5\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-5%29+=+%282%2825%29-1%29%2F%2825%29\" See note below\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-5%29+=+%2850-1%29%2F%2825%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-5%29+=+49%2F25\"\r
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\n" ); document.write( "\n" ); document.write( "Note: squaring something like -5 yields a positive result since (-5)^2 = (-5)*(-5) = +25\r
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\n" ); document.write( "\n" ); document.write( "(c)\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29+=+%282x%5E2-1%29%2F%28x%5E2%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-x%29+=+%282%28-x%29%5E2-1%29%2F%28%28-x%29%5E2%29\" Replace EVERY copy of x with -x\r
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\n" ); document.write( "\n" ); document.write( "Now because \"%28-x%29%5E2+=+x%5E2\" (based on the note above) this means that we end up with \r
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\n" ); document.write( "\n" ); document.write( "\"f%28-x%29+=+%282x%5E2-1%29%2F%28x%5E2%29\"\r
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\n" ); document.write( "\n" ); document.write( "which is the same as the original function. Only the left side is different. Because \"f%28-x%29+=+f%28x%29\", for all values of x in the domain of f(x), this means that f(x) is an even function. It is symmetric with respect to the y axis.
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