document.write( "Question 927655: please solve the symmetry and odd even or neither for the following equation:
\n" ); document.write( "x^3 - 9x / 4x^2 - 4x - 80
\n" ); document.write( "

Algebra.Com's Answer #563135 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Let \"f%28x%29+=+%28x%5E3+-+9x%29%2F%284x%5E2+-+4x+-+80%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "To prove an function is odd, we need to show that \"f%28-x%29+=+-f%28x%29\". So let's first find \"f%28-x%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"f%28x%29+=+%28x%5E3+-+9x%29%2F%284x%5E2+-+4x+-+80%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"f%28-x%29+=+%28%28-x%29%5E3+-+9%28-x%29%29%2F%284%28-x%29%5E2+-+4%28-x%29+-+80%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"f%28-x%29+=+%28-x%5E3+%2B+9%29%2F%284x%5E2+%2B+4x+-+80%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Now let's find \"-f%28x%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"f%28x%29+=+%28x%5E3+-+9x%29%2F%284x%5E2+-+4x+-+80%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-f%28x%29+=+-%28x%5E3+-+9x%29%2F%284x%5E2+-+4x+-+80%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"-f%28x%29+=+%28-x%5E3+%2B+9x%29%2F%284x%5E2+-+4x+-+80%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So we can see that \"f%28-x%29%3C%3E-f%28x%29\" (notice how the +4x and -4x in the denominators don't match).\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Therefore, \"f%28x%29\" is NOT an odd function.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "------------------------------------------------------------------------------------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "To show that an function is even, we need to show that \"f%28-x%29+=+f%28x%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "From the last part, we found that \"f%28-x%29+=+%28-x%5E3+%2B+9%29%2F%284x%5E2+%2B+4x+-+80%29\" but this is not equal to \"f%28x%29+=+%28x%5E3+-+9x%29%2F%284x%5E2+-+4x+-+80%29\". \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The numerators don't match at all in terms of their signs and the denominators are off too a bit (again the +4x and -4x).\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Therefore, \"f%28x%29\" is NOT an even function.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "------------------------------------------------------------------------------------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Summary: Above we've shown that \"f%28x%29\" is neither even nor odd. \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Because of this, it does NOT have y axis symmetry (it's not even) and it does NOT have origin symmetry (it's not odd).\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The graph visually sums it all up for us without having to say a single word. It looks like the graph has origin symmetry, but it's approximately symmetric for \"-3%3C=x%3C=3\". Any x outside this interval has this symmetry breaking down.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "From \"x+=+-3\" to \"x+=+3\", this graph looks pretty symmetric (with respect to the origin), but as x goes beyond +4, the curve does not go beyond -4 to reciprocate which is where the symmetry starts to break down.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "A more basic and quick indication is to notice how the vertical asymptotes \"x+=+-4\" and \"x+=+5\" are not equal in magnitude. Ie, \"abs%28-4%29+%3C%3E+abs%285%29\", so this also tells us f(x) does not have origin symmetry.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "------------------------------------------------------------------------------------------------------------------------\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "If you need more one-on-one help, email me at jim_thompson5910@hotmail.com. You can ask me a few more questions for free, but afterwards, I would charge you ($2 a problem to have steps shown or $1 a problem for answer only).\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Alternatively, please consider visiting my website: http://www.freewebs.com/jimthompson5910/home.html and making a donation. Any amount is greatly appreciated as it helps me a lot. This donation is to support free tutoring. Thank you.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Jim\r
\n" ); document.write( "\n" ); document.write( "------------------------------------------------------------------------------------------------------------------------
\n" ); document.write( "
\n" );