document.write( "Question 77193: For the equation x-2sqrtx=0 , perform the following:
\n" ); document.write( "a) Solve for all values of x that satisfies the equation.
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\n" ); document.write( "\n" ); document.write( "b) Graph the functions y = x and on the same graph (by plotting points if necessary). Show the points of intersection of these two graphs.
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\n" ); document.write( "Points of intersection:
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Algebra.Com's Answer #55311 by bucky(2189)\"\" \"About 
You can put this solution on YOUR website!
First part of the problem:
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\n" ); document.write( "Given:
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\n" ); document.write( "\"x+-+2%2Asqrt%28x%29+=+0\"
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\n" ); document.write( "Find all the values of x that satisfy this equation.
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\n" ); document.write( "The method involves getting the radical term on one side of the equation and the other term
\n" ); document.write( "on the other side. We can do this by adding \"2%2Asqrt%28x%29\" to both sides and the equation
\n" ); document.write( "then becomes:
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\n" ); document.write( "\"x+=+2%2Asqrt%28x%29\"
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\n" ); document.write( "Next square both sides. Note that when you do that, the right side squares as follows:
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\n" ); document.write( "\"%282%2Asqrt%28x%29%29%5E2+=+%282%5E2%29%2A%28sqrt%28x%29%29%5E2+=+4%2Ax\"
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\n" ); document.write( "and the equation therefore squares to:
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\n" ); document.write( "\"x%5E2+=+4x\"
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\n" ); document.write( "Subtract 4x from both sides and the equation is then:
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\n" ); document.write( "\"x%5E2+-+4x+=+0\"
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\n" ); document.write( "Factor the common \"x\" from both terms on the left side to get:
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\n" ); document.write( "\"x%2A%28x+-+4%29+=+0\"
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\n" ); document.write( "Note that this equation will be true if either of the factors is zero. Therefore,
\n" ); document.write( "one at a time we can set the factors equal to zero to solve the equation. First:
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\n" ); document.write( "\"x+=+0\"
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\n" ); document.write( "That is one answer. Then:
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\n" ); document.write( "\"x-4+=+0\"
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\n" ); document.write( "Solve by adding 4 to both sides to get:
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\n" ); document.write( "\"x+=+4\"
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\n" ); document.write( "So the answer to the first part of this problem is that the equation given in the problem
\n" ); document.write( "will be satisfied by two values of x ... x = 0 and x = 4.
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\n" ); document.write( "For the second part of the problem the two graphs should look like this:
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\n" ); document.write( "\"graph%28600%2C400%2C-1%2C20%2C-5%2C+20%2C+x%2C+x+-+2%2Asqrt%28x%29%29\"
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\n" ); document.write( "Note that the original equation given in the problem does not permit x to be less than
\n" ); document.write( "zero because for real values you are not permitted to take the square root of a negative
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\n" ); document.write( "The red line is the graph of \"y+=+x\" and the green line is the graph of \"y+=+x+-+2%2Asqrt%28x%29\"
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\n" ); document.write( "Note that the green line is on the x-axis at the two values of x that we found previously,
\n" ); document.write( "x = 0 and x = +4. Also note that the only place the two equations intersect is at the
\n" ); document.write( "origin. You can also show this is true mathematically by solving the equation set:
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\n" ); document.write( "\"y+=+x\" and \"y+=+x+-+2%2Asqrt%28x%29\"
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\n" ); document.write( "Solve by substitution. The first equation tells us that y equals x so we can substitute
\n" ); document.write( "x for y in the second equation. With this substitution, the second equation becomes:
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\n" ); document.write( "\"x+=+x+-+2%2Asqrt%28x%29\"
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\n" ); document.write( "Subtract x from both sides and the equation reduces to:
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\n" ); document.write( "\"0+=+-2%2Asqrt%28x%29\"
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\n" ); document.write( "Square both sides and you get:
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\n" ); document.write( "\"+0+=+4%2Ax\"
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\n" ); document.write( "and divide both sides by 4 to find that:
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\n" ); document.write( "\"x+=+0\"
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\n" ); document.write( "Then you can solve for the corresponding value of y by returning to the equation \"y+=+x\"
\n" ); document.write( "and plugging in 0 for x to find that y also = 0. The only common point on the two graphs
\n" ); document.write( "is (0,0) ... the origin as is shown on the graphs themselves.
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\n" ); document.write( "Hope this helps you to understand the problem and how to go about getting the solution
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