document.write( "Question 557449: Range of function sqrt(x^2-2x+5). Why is the range ≥2?, without graphing \n" ); document.write( "
Algebra.Com's Answer #362610 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
i cheated by graphing it.
\n" ); document.write( "now i see what's going on.
\n" ); document.write( "what is happening is that the range of the function will be >= 2 because the value of y will never get below 2.
\n" ); document.write( "the domain of this function is all values of x such that the sqrt(x^2-2x+5) is positive.
\n" ); document.write( "that will occur at all values of x.
\n" ); document.write( "when x = -5, the value of y is equal to 6.3245553
\n" ); document.write( "when x = 0, the value of y is equal to 2.236068
\n" ); document.write( "when x = 5, the value of y is equal to 4.472136
\n" ); document.write( "the minimum value of y occurs when x = = 1
\n" ); document.write( "y never gets below 2.
\n" ); document.write( "y can go as high as you want, depending on the value of x.
\n" ); document.write( "for example:
\n" ); document.write( "when x = -500, y = 501.00399
\n" ); document.write( "when x = 500, y = 499.00401
\n" ); document.write( "when x = -5000, y = 5001.0004
\n" ); document.write( "when x = 5000, y = 49999.0004
\n" ); document.write( "the greater the value of x, the closer y will get to the absolute value of x.
\n" ); document.write( "so, if x can go infinite in each direction, this means that y can go infinite in the positive direction, because y will always be positive.
\n" ); document.write( "on the reverse side, there is no value of x that will provide a value of y smaller than 2.
\n" ); document.write( "that is why the range of the function is >= 2.
\n" ); document.write( "we are talking about the range of the function which is the value of y or is the value of f(x) which is equal to y.
\n" ); document.write( "the domain is the value of x which can be any real number.
\n" ); document.write( "the graph of this equation, by the way, looks like this:
\n" ); document.write( "\"graph%28600%2C600%2C-5%2C5%2C-5%2C5%2Csqrt%28x%5E2-2x%2B5%29%29\"
\n" ); document.write( "as x gets more negative and as x gets more positive, the value of y will get more positive.
\n" ); document.write( "
\n" ); document.write( "
\n" );