document.write( "Question 1120210: Find all values of x for which sqrt(x-3) > (x-5) \n" ); document.write( "
Algebra.Com's Answer #735890 by ikleyn(52781)\"\" \"About 
You can put this solution on YOUR website!
.
\n" ); document.write( "I wrote my first solution to this problem . . .
\n" ); document.write( "Then I saw that is was not exactly correct.   Therefore,  I deleted it.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Then I developed my second solution,  which is in this post.  Hope,  it is correct.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\r\n" );
document.write( "Fist of all, since the condition does not state an opposite, I will assume that only positive branch \r\n" );
document.write( "of the square root  \"sqrt%28x-3%29\"  is under consideration.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Then the solution consists of thee steps.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "1.  The domain of the left side square root is the set of real numbers  x >= 3.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "2.  The set of those \"x\" what make the right side negative is\r\n" );
document.write( "\r\n" );
document.write( "    x - 5 < 0  ====>  x < 5.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    Thus the set  3 <= x < 5  is the part of the solution set to the given inequality, since the left side then exist and is positive,\r\n" );
document.write( "\r\n" );
document.write( "    while the right side is negative.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "3.  Now we will assume that  x >= 5.  Then both sides of the given inequality are positive.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    Square both sides.  Since both sides were positive, we have a valid inequality in the domain  x >= 5\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    x- 3 > \"%28x-5%29%5E2\",\r\n" );
document.write( "\r\n" );
document.write( "    x-3 > x^2 - 10x + 25,\r\n" );
document.write( "\r\n" );
document.write( "    0 > x^2 - 11x + 28,\r\n" );
document.write( "\r\n" );
document.write( "    x^2 - 11x + 28 < 0,\r\n" );
document.write( "\r\n" );
document.write( "    Factor left side\r\n" );
document.write( "\r\n" );
document.write( "    (x-4)*(x-7) < 0\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "    The solution is this interval  4 < x < 7.\r\n" );
document.write( "
\r
\n" ); document.write( "\n" ); document.write( "Thus the final solution is the union of these sets   3 <= x < 5  and   4 < x <7.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "This union is the interval   3 <= x < 7.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Thus the final  ANSWER  is  THIS:   3 <= x < 7.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Let us check if we get the full set solution correctly.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "I made this check graphically. Below please find the plots of the functions y = \"sqrt%28x-3%29\" (red line) and the function y = x-5 (green line).\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The solution set is those values of \"x\" on the x-axis,  where the first plot is above the second one.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\r\n" );
document.write( "  \r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "  Plot of original functions y = \"sqrt%28x-3%29\" (red)  and  y = x-5 (green)\r\n" );
document.write( "
\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Visual check confirms that the interval  3 <= x < 7 is the full set of solutions.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );