document.write( "Question 969699: Lim Sqrt{4x+1}-3 / x-2
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document.write( "x--->2\r
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document.write( "How do i do this. I cant figure out how to get rid of the sqrt. I looked online and everyone says to rationalize the numerator but they skip steps so idk what I'm supposed to do. Can someone explain without skipping a step even if it seems easy to you. \n" );
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Algebra.Com's Answer #592503 by Theo(13342)![]() ![]() You can put this solution on YOUR website! find the limit of sqrt(4x+1)-3 / (x-2) as x approaches 2.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "i believe that what they told you is a correct way to look at it.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "if you were able to graph the function, you would have found that the answer should be 2/3 or thereabouts.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "that's just by eyeballing.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "algebraically, you would do the following:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "start with:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(sqrt(4x+1)-3) / (x-2)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "multiply numerator and denominator by (sqrt(4x+1)+3) to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "((sqrt(4x+1)-3)*(sqrt(4x+1)+3)) / ((x-2)*(sqrt(4x+1)+3))\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "((4x+1)-9) / ((x-2)*(sqrt(4x+1)+3))\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify further to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(4x-8) / ((x-2)*(sqrt(4x+1)+3))\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "factor out a 4 in the numerator to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "4*(x-2) / ((x-2)*(sqrt(4x+1)+3))\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the (x-2) in the numerator and denominator cancel out and you are left wtih:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "4 / (sqrt(4x+1)+3))\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "when x = 2, this becomes 4 / (sqrt(9)+3)) which becomes 4 / (3+3) which becomes 4/6 which becomes 2/3.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "that's your solution.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the limit of (sqrt(x+1)-3) / (x-2) as x approaches 2 is equal to 2/3.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in the graph, you can see that there is a hole at x = 2, and if you gave values of x as 1.999999999 and 2.000000001, you would see that they hovered about 2/3.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the graph looks like this:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the horizontal line is at y = 2/3.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you can see that the graph of y = 2/3 intersects with the graph of y = (sqrt(4x+1)-3)/(x-2) at x = 2.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you will not, however, be able to find that value since the function is undefined at x = 2. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "there is a hole there that you can't see.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the hole is because when you try to evaluate the function at x = 2, the answer is undefined.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "it does, however, show you that, as you approach x = 2, the answer will approach x = 2/3.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |