document.write( "Question 138649: Find if the function is even, odd or neither.\r
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\n" ); document.write( "\n" ); document.write( "f(x)=x^3+4x
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Algebra.Com's Answer #101175 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "Remember, if \"f%28x%29=f%28-x%29\" then the function is an even function. If \"f%28-x%29=-f%28x%29\" then the function is an odd function.\r
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\n" ); document.write( "\n" ); document.write( "First, let's see if \"f%28x%29=x%5E3%2B4x\" is an even function.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29=x%5E3%2B4x\" Start with the given function.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-x%29=%28-x%29%5E3%2B4%28-x%29\" Replace each x with -x.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-x%29=-x%5E3-4x\" Simplify. Note: only the terms with an odd exponent will change in sign.\r
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\n" ); document.write( "\n" ); document.write( "Since \"f%28x%29%3C%3Ef%28-x%29\", this shows us that \"f%28x%29=x%5E3%2B4x\" is not an even function.\r
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\n" ); document.write( "\n" ); document.write( "Now, let's see if \"f%28x%29=x%5E3%2B4x\" is an odd function.\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29=x%5E3%2B4x\" Start with the given function.\r
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\n" ); document.write( "\n" ); document.write( "\"-f%28x%29=-%28x%5E3%2B4x%29\" Negate the entire function by placing a negative outside the function.\r
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\n" ); document.write( "\n" ); document.write( "\"-f%28x%29=-x%5E3-4x\" Distribute and simplify.\r
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\n" ); document.write( "\n" ); document.write( "Since f(-x)=-f(x), this shows us that \"f%28x%29=x%5E3%2B4x\" is an odd function.\r
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\n" ); document.write( "\n" ); document.write( "So the function \"f%28x%29=x%5E3%2B4x\" is an odd function.
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