document.write( "Question 87302: Determine the symmetry (relative to the x-axis, y-axis, and/or origin) of the graph of the function. No need for graph. f(x)= x^3 + x \n" ); document.write( "
Algebra.Com's Answer #63241 by jim_thompson5910(35256)\"\" \"About 
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Remember, a function is even when this equality is true:\r
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\n" ); document.write( "\n" ); document.write( "\"f%28x%29=f%28-x%29\"\r
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\n" ); document.write( "\n" ); document.write( "and a function is odd when this equality is true:\r
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\n" ); document.write( "\n" ); document.write( "\"-f%28x%29=f%28-x%29\"\r
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\n" ); document.write( "\n" ); document.write( "Lets see if the function is even:\r
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\n" ); document.write( "\n" ); document.write( "\"y=x%5E3%2Bx\" Start with the given equation\r
\n" ); document.write( "\n" ); document.write( "Here's \"f%28x%29\":\r
\n" ); document.write( "\n" ); document.write( "\"f%28x%29=x%5E3%2Bx\" This is the given equation\r
\n" ); document.write( "\n" ); document.write( "Here's \"f%28-x%29\":\r
\n" ); document.write( "\n" ); document.write( "\"f%28-x%29=%28-x%29%5E3%2B%28-x%29\" Replace x with \"-x\"\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-x%29=-x%5E3-x\" Simplify\r
\n" ); document.write( "\n" ); document.write( "Since \"x%5E3%2Bx\" does not equal \"-x%5E3-x\", this means the equation \"f%28x%29=f%28-x%29\" is not true.\r
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\n" ); document.write( "\n" ); document.write( "Since \"f%28x%29\" does not equal \"f%28-x%29\", the equation \"y=x%5E3%2Bx\" is not an even function.\r
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\n" ); document.write( "\n" ); document.write( "Now lets see if the function is odd:\r
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\n" ); document.write( "\n" ); document.write( "\"y=x%5E3%2Bx\" Start with the given equation\r
\n" ); document.write( "\n" ); document.write( "Here's \"f%28-x%29\":\r
\n" ); document.write( "\n" ); document.write( "\"f%28-x%29=-x%5E3-x\" Remember we solved for this previously\r
\n" ); document.write( "\n" ); document.write( "Here's \"-f%28x%29\":\r
\n" ); document.write( "\n" ); document.write( "\"-f%28x%29=-%28x%5E3%2Bx%29\" Negate the whole function\r
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\n" ); document.write( "\n" ); document.write( "\"f%28-x%29=-x%5E3-x\" Distribute the negative and simplify\r
\n" ); document.write( "\n" ); document.write( "Since \"-x%5E3-x\" equals \"-x%5E3-x\", this means the equation \"-f%28x%29=f%28-x%29\" is true.\r
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\n" ); document.write( "\n" ); document.write( "Since \"-f%28x%29\" equals \"f%28-x%29\", the equation \"y=x%5E3%2Bx\" is an odd function. This means the equation has symmetry with respect to the origin.\r
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\n" ); document.write( "\n" ); document.write( "When we graph the equation \"y=x%5E3%2Bx\", we can see if the equation has any symmetry:\r
\n" ); document.write( "\n" ); document.write( "\"+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C+x%5E3%2Bx%29+\"\r
\n" ); document.write( "\n" ); document.write( "and we can clearly see that the equation is symmetrical with respect to the origin\r
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