document.write( "Question 1089814: 3.
\n" );
document.write( "Solve the following inequality\r
\n" );
document.write( "\n" );
document.write( "42x -13 < 42/x \r
\n" );
document.write( "\n" );
document.write( "•Is the point x = 0 included in the solution set of the inequality?
\n" );
document.write( "Yes or No\r
\n" );
document.write( "\n" );
document.write( "•Are the other finite end points of the intervals included in the solution set? Yes or No\r
\n" );
document.write( "\n" );
document.write( "•What is the solution set? __________\r
\n" );
document.write( "\n" );
document.write( "Answer in interval notation and Show work.
\n" );
document.write( " \n" );
document.write( "
Algebra.Com's Answer #704197 by Theo(13342)![]() ![]() You can put this solution on YOUR website! set 42x - 13 equal to 42/x.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "find the intersection points.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "then find the area before, between, and beyond these intersection points that satisfy the criteria.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "start with 42x - 13 = 42/x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "multiply both sides of the equation by x to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x * (42x - 13) = 42\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "subtract 42 from both sides of the equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x * (42x - 13) - 42 = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "42x^2 - 13x - 42 = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve this quadratic equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = 1.1666666666667 or x = -0.85714285714286\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "42x -13 is equal to 42/x when x = 1.1666666666667 or x = -0.85714285714286\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the intervals you need to test are:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x < -0.85714285714286\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x > 1.1666666666667\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x between -0.85714285714286 and 1.1666666666667\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = -1 is less than -.857, so try that first.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x = -1:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "42x - 13 is equal to -55. \n" ); document.write( "42 / x is equal to -42.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "therefore 42x - 13 is less than 42 / x when x < -.857.....\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = 0 is between x = -.857... and 1.166 ..., so try that next.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x = 0:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "42x - 13 is equal to -13. \n" ); document.write( "42 / x is undefined.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "***** 0 can't be used because 42 / x is undefined when x = 0.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the interval between -.857... and 1.166.... has to be split into two intervals.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "those intervals would be x > -.857 and < 0, and x > 0 and < 1.166...\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "try x = 1 because 1 is greater than 0 and less than x = 1.166....\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x = 1:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "42x - 13 = 29 \n" ); document.write( "42/x = 42\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "42x - 13 is less than 42/x when x is greater than 0 and less then 1.166...\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "next try x = -0.5 because -.5 is greater than -.857... and less than 0.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x = -.5:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "42x - 13 = -34 \n" ); document.write( "42 / x = -84\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "42x - 13 is not less then 42 / x when x is between -.857 and 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = 2 is greater than x = 1.66...., so try that next.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x = 2:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "42x - 13 = 71 \n" ); document.write( "42/x = 24\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "42x - 13 is not less than 42/x when x is equal to 2.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this suggests that your solution will be when:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x is less than -.857... \n" ); document.write( "x is greater than 0 and less than 1.166....\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this can be seen graphically in the following two graphs.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the first is the graph of the quadratic equation of y = 42x^2 - 13x - 42\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the second is the graph of y = 42x - 13 and y = 42/x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "remember that if a = b then a - b = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "that's the premise behind the creation of the quadratic equation from 42x - 13 = 42/x.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "here's the graphs:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " ![]() \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " ![]() \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "they both give you the same intersection points.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "however, the graph of the quadratic equation, while very useful, doesn't show where the original equations have an undefined value.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the answers to your questions are:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "•Is the point x = 0 included in the solution set of the inequality? \n" ); document.write( "Yes or No \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the answer is no because the value of 42/x is undefined when x = 0.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "•Are the other finite end points of the intervals included in the solution set? Yes or No \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the finite end points are not included in the solution set because the inequality is less than rather than less than or equal.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "•What is the solution set? __________ \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the solution set is:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x < -0.85714285714286 or x > 0 and < x < 1.1666666666667\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in interval notation this would be:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x = ( minus infinity, -0.85714285714286) or (0, 1.1666666666667)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x cannot be equal to 0 because then 42/x is undefined.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x cannot be equal to -0.85714285714286 because than 42x - 13 = 42/x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x cannot be equal to 1.1666666666667 because then 42x - 13 = 42/x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this last graph shows the areas where 42x - 13 < 42 / x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " ![]() \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \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( " \n" ); document.write( " |