document.write( "Question 461376: Using the formula \"f%28x%29=x%5E2-2x%2B1\", find if it has a maximum or minimum and give that point. Also give x-intercepts. \n" ); document.write( "
Algebra.Com's Answer #316436 by math-vortex(648)\"\" \"About 
You can put this solution on YOUR website!
Using the formula \"f%28x%29=x%5E2-2x%2B1\", find if it has a maximum or minimum and give that point. Also give x-intercepts.\r
\n" ); document.write( "\n" ); document.write( "--------------------------
\n" ); document.write( "Find minimum/maximum point
\n" ); document.write( "--------------------------
\n" ); document.write( "This function represents a the standard form of an equation for a parabola, \"f%28x%29=ax%5E2%2Bbx%2Bc\".
\n" ); document.write( ".
\n" ); document.write( "There is an easy way to tell if the parabola has a maximum or a minimum when the equation is in this form. If the coefficient of the x-squared term is positive the parabola opens upward, and the the function has a minimum at the vertex. If the coefficient is negative, the parabola opens downward, and the the function has a maximum value.
\n" ); document.write( ".
\n" ); document.write( "In your equation, the coefficient is 1 because you have \"x%5E2\". (Remember, if no coefficient is shown, it is understood to be 1.) Your parabola opens upward, and the function has a minimum value.
\n" ); document.write( ".
\n" ); document.write( "Parabolas have one maximum or minimum value located at the vertex. To find the vertex of your parabola, we use the formula, x = -b/2a. Looking at the equation, we see that b is -2 and a is 1, so x = -b/2a = -(-2)/(2(1)) = 1. To find the y-value of the vertex, substitute 1 for x in the equation.
\n" ); document.write( ".
\n" ); document.write( "\"y=x%5E2-2x%2B1=%281%29%5E2-2%281%29%2B1%29=0\"
\n" ); document.write( ".
\n" ); document.write( "---------------------
\n" ); document.write( "Find the x-intercepts
\n" ); document.write( "---------------------
\n" ); document.write( "The x-intercepts are the points where the parabola intersects the x-axis. To find the x-intercepts we set f(x) = 0. and solve for x.
\n" ); document.write( ".
\n" ); document.write( "\"f%28x%29=x%5E2-2x%2B1\"
\n" ); document.write( ".
\n" ); document.write( "Set the function equal to zero.
\n" ); document.write( "\"0=x%5E2-2x%2B1\"
\n" ); document.write( ".
\n" ); document.write( "Invert the order of the equation.
\n" ); document.write( "\"x%5E2-2x%2B1=0\"
\n" ); document.write( ".
\n" ); document.write( "This is a quadratic equation. We have two choices for solving it: factoring, or the quadratic formula. In this case the equation looks pretty east to factor.
\n" ); document.write( "\"%28x-1%29%28x-1%29=0\"
\n" ); document.write( ".
\n" ); document.write( "Notice that both factors are the same, so
\n" ); document.write( "\"x-1=0\"
\n" ); document.write( "\"x=1\"
\n" ); document.write( ".
\n" ); document.write( "This tells us that when f(x) is 0, x is 1 and the x-intercept is the point (1,0).
\n" ); document.write( ".
\n" ); document.write( "A quick check using substitution, gives us
\n" ); document.write( "\"f%28x%29=x%5E2-2x%2B1\"
\n" ); document.write( ".
\n" ); document.write( "\"0=%281%29%5E2-2%281%29%2B1\"
\n" ); document.write( ".
\n" ); document.write( "\"0=1-2%2B1\"
\n" ); document.write( ".
\n" ); document.write( "\"0=0\" (true)\r
\n" ); document.write( "\n" ); document.write( "Take a look at the graph:
\n" ); document.write( ".
\n" ); document.write( ".
\n" ); document.write( "\"graph%28+300%2C+300%2C+-5%2C+5%2C+-5%2C+5%2C+x%5E2-2x%2B1%29\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Hope this helps!\r
\n" ); document.write( "\n" ); document.write( "Ms. Figgy
\n" ); document.write( "math-in-the-vortex
\n" ); document.write( "
\n" );