document.write( "Question 127200: One root of the function y=x^2-10x+k is 5+2isqrt3. What is the value of k???? \n" ); document.write( "
Algebra.Com's Answer #93191 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! One root of the function y=x^2-10x+k is 5+2isqrt3. What is the value of k???? \n" ); document.write( "----------------- \n" ); document.write( "If 5+2sqrt(3)i is a root, so is 5-2sqrt(3)i. \n" ); document.write( "---------------- \n" ); document.write( "Then the following product is a factor of the given polynomial: \n" ); document.write( "(x-(5+2sqrt(3)i)(x-(5-2sqrt(3)i)\r \n" ); document.write( "\n" ); document.write( "= ((x-5)-2sqrt(3)i)((x-5)+2sqrt(3)i) \n" ); document.write( "Comment: Notice that the factors are in the form (a-b)(a+b). \n" ); document.write( "So the product is a^2-b^2 \n" ); document.write( "-----------------------\r \n" ); document.write( "\n" ); document.write( "= (x-5)^2 -(2sqr(3)i)^2\r \n" ); document.write( "\n" ); document.write( "= x^2-10x+25+12\r \n" ); document.write( "\n" ); document.write( "= x^2-12x+37\r \n" ); document.write( "\n" ); document.write( "Comparing that to the original polynominal you see that \n" ); document.write( "k = 37 \n" ); document.write( "=========== \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( " |