document.write( "Question 985083: how do i analyze a rational function?\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "

Algebra.Com's Answer #605928 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!
Analyzing the graph of a rational function
\n" ); document.write( "step 1: Find the domain of the rational function
\n" ); document.write( "step 2: Write R in lowest terms (simplify the rational function if possible)
\n" ); document.write( "step 3: Locate the intercepts of the graph.
\n" ); document.write( "step 4: Test for symmetry
\n" ); document.write( "step 5: Locate the vertical asymptotes
\n" ); document.write( "step 6: Locate the horizontal or oblique asymptotes
\n" ); document.write( "step 7: Determine points, if any, where the graph crosses the asymptotes
\n" ); document.write( "(horizontal or oblique)\r
\n" ); document.write( "\n" ); document.write( "here is an example:\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "analyze the graph of a rational function\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"R%28x%29=%28x-1%29%2F%28x%5E2-4%29\" \r
\n" ); document.write( "\n" ); document.write( "step 1: Find the domain of the rational function\r
\n" ); document.write( "\n" ); document.write( "domain is:\r
\n" ); document.write( "\n" ); document.write( "{ \"x\"| \"x%3C%3E2\" and \"x%3C%3E-2\"\r
\n" ); document.write( "\n" ); document.write( "step 2: Write R in lowest terms (simplify the rational function if possible)\r
\n" ); document.write( "\n" ); document.write( "\"R%28x%29=%28x-1%29%2F%28%28x%2B2%29%28x-2%29%29+\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "step 3: Locate the intercepts of the graph.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"R%280%29=%280-1%29%2F%28%280%2B2%29%280-2%29%29+\"\r
\n" ); document.write( "\n" ); document.write( "\"R%280%29=%28-1%29%2F%282%28-2%29%29+\"\r
\n" ); document.write( "\n" ); document.write( "\"R%280%29=%28-1%29%2F%28-4%29+\"\r
\n" ); document.write( "\n" ); document.write( "\"R%280%29=1%2F4+\"-> y-intercept is at (\"0\",\"1%2F4\")\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"0=%28x-1%29%2F%28%28x%2B2%29%28x-2%29%29+\"\r
\n" ); document.write( "\n" ); document.write( "\"0%28%28x%2B2%29%28x-2%29%29+=%28x-1%29+\"\r
\n" ); document.write( "\n" ); document.write( "\"0+=x-1\"\r
\n" ); document.write( "\n" ); document.write( "\"x=1\"-> x-intercept is at (\"1\",\"0\")\r
\n" ); document.write( "\n" ); document.write( "step 4: Test for symmetry\r
\n" ); document.write( "\n" ); document.write( "if \"R%28-x%29+=+R%28x%29\" the function has symmetry about the y­-axis
\n" ); document.write( "find \"R%28-x%29\"
\n" ); document.write( "\"R%28-x%29=%28-x-1%29%2F%28%28-x%29%5E2-4%29\"
\n" ); document.write( "\"R%28-x%29=-%28x%2B1%29%2F%28x%5E2-4%29+\"
\n" ); document.write( "so, \"R%28-x%29+%3C+%3E+R%28x%29\" => \"no\" symmetry\r
\n" ); document.write( "\n" ); document.write( "and \"R%28-x%29%3C%3E-R%28x%29\", the function has \"no\" symmetry about the origin \r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "step 5: Locate the vertical asympthote\r
\n" ); document.write( "\n" ); document.write( "\"%28x%2B2%29%28x-2%29=0\"=>\"x=2\" and \"x=-2\" are the vertical asympthotes\r
\n" ); document.write( "\n" ); document.write( "for next step:
\n" ); document.write( "Horizontal and Oblique Asympthote reminder(the degree of the numerator is \"n\"
\n" ); document.write( "and the degree of the denominator is \"m\")
\n" ); document.write( "1.
\n" ); document.write( "If \"n+%3C+m\", then \"R\" is a proper fraction and will have the horizontal asympthote \"y+=+0\".
\n" ); document.write( "2.
\n" ); document.write( "If \"n+%3Em\", then R is improper and long division is used.
\n" ); document.write( "(a)
\n" ); document.write( "If \"n+=+m\", the quotient obtained will be a number, and the line y = is a horizontal asymptote.
\n" ); document.write( "(b)
\n" ); document.write( "If \"n+=+m+%2B+1\", the quotient obtained is of the form \"ax+%2B+b\"(a polynomial of degree 1), and the line \"y+=+ax+%2B+b\" is an oblique asymptote.
\n" ); document.write( "(c)
\n" ); document.write( "If\"+n+%3E+m+%2B+1\", the quotient obtained is a polynomial of degree 2 or higher and R has
\n" ); document.write( "neither a horizontal nor an oblique asymptote.\r
\n" ); document.write( "\n" ); document.write( " Horizontal asymptote:\r
\n" ); document.write( "\n" ); document.write( "\"%28x-1%29%2F%28%28x-2%29+%28x%2B2%29%29-%3E0\" as \"x\"->±\"infinity\"
\n" ); document.write( "so, horizontal asymptote is \"y=0\"\r
\n" ); document.write( "\n" ); document.write( "no oblique asymptotes found \r
\n" ); document.write( "\n" ); document.write( "step 7: Determine points, if any, where the graph crosses the asymptotes\r
\n" ); document.write( "\n" ); document.write( "\"x-1=0\"
\n" ); document.write( "\"x=1\"\r
\n" ); document.write( "\n" ); document.write( "\"0=%28x-1%29%2F%28%28x-2%29+%28x%2B2%29%29\"\r
\n" ); document.write( "\n" ); document.write( "graph:\r
\n" ); document.write( "\n" ); document.write( "\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );