document.write( "Question 175746This question is from textbook Algebra 2
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document.write( ": How do I graph this polynomial function? f(x)=x^4 - 2x^3 - 3x^2 + 5x + 2.
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document.write( "Thank you very much. \n" );
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Algebra.Com's Answer #130891 by nabla(475)![]() ![]() ![]() You can put this solution on YOUR website! 1) Factor to f(x)=(-2 + x) (-1 - 3 x + x^3) \n" ); document.write( "2) The first evident, real root will be x=2. \n" ); document.write( "3) It should be noted that this will \"eventually\" resemble a parabola. Moreover, our interest will be around x=2. \n" ); document.write( "4) Techniques of calculus will give us concavity, max, min, inflection.\r \n" ); document.write( "\n" ); document.write( "f'(x)=4x^3-6x^2-6x+5=0 gives criticals of\r \n" ); document.write( "\n" ); document.write( "x -> -1.05274 \n" ); document.write( "x -> 0.611731 \n" ); document.write( "x -> 1.94101\r \n" ); document.write( "\n" ); document.write( "If you test outside the intervals you will note changes in direction of the slope this is indicative of extrema. \n" ); document.write( "Thus: x=-1.05274 is local minimum \n" ); document.write( "x=0.611731 is local maximum \n" ); document.write( "x=1.94101 is local minimum\r \n" ); document.write( "\n" ); document.write( "Concavity [not entirely necessary]: \n" ); document.write( "f''(x)=12x^2-12x-6=0 \n" ); document.write( "gives \n" ); document.write( "x -> -0.366025 \n" ); document.write( "x -> 1.36603\r \n" ); document.write( "\n" ); document.write( "Testing intervals again you will find CU on (-inf, -0.366025), CD on (-0.366025, 1.36603), then CU on (1.36603, inf).\r \n" ); document.write( "\n" ); document.write( "This is certainly enough information to produce the following graph:\r \n" ); document.write( "\n" ); document.write( " |