document.write( "Question 825719: If x= sqrt(6) is a root of x^3-5x^2-6x+30=0, use synthetic division to factor the polynomial completely and list all real solutions of the equation. \n" ); document.write( "
Algebra.Com's Answer #497570 by jsmallt9(3758)![]() ![]() ![]() You can put this solution on YOUR website! \r\n" ); document.write( "sqrt(6) | 1 -5 -6 30\r\n" ); document.write( "--------- sqrt(6) 6-5sqrt(6) -30\r\n" ); document.write( " ------------------------------------\r\n" ); document.write( " 1 -5+sqrt(6) -5sqrt(6) 0\r\n" ); document.write( "The remainder is zero (in the lower right corner) which means our (x-sqrt(6)) divided evenly into our expression (as we knew it would since it is a root). The rest of the bottom row, \"1 -5+sqrt(6) -5sqrt(6)\", is the quotient. \n" ); document.write( "If a polynomial with rational coefficients, like our expression, has a square root for a root, then the negative of that square root will also be a root. So we will now divide our quotient by (x-(-sqrt(6))): \n" ); document.write( " \r\n" ); document.write( "-sqrt(6)| 1 -5+sqrt(6) -5sqrt(6)\r\n" ); document.write( "--------- -sqrt(6) 5sqrt(6)\r\n" ); document.write( " ------------------------------------\r\n" ); document.write( " 1 -5 0\r\n" ); document.write( "The quotient, \"1 -5\", translates into x-5. This makes the last root a 5. \n" ); document.write( "So the roots of our expression are: 5, sqrt(6) and -sqrt(6) (which are all real numbers). \n" ); document.write( "P.S. This is a polynomial, not a rational function. Please use an appropriate category when posting problems. \n" ); document.write( " \n" ); document.write( " |