document.write( "Question 468430: I have to complete the square to change the form of the function and grph the quadractic function????\r
\n" ); document.write( "\n" ); document.write( "f(x) = -2x^2 -5x +1 \n" ); document.write( "

Algebra.Com's Answer #321428 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

You can put this solution on YOUR website!
f(x) = -2x^2 - 5x + 1
\n" ); document.write( ":
\n" ); document.write( "-2x^2 - 5x + ___ = -1
\n" ); document.write( "divide by -2, change the signs
\n" ); document.write( "x^2 + $\"5%2F2\"$ x + ___ = $\"1%2F2\"$
\n" ); document.write( ":
\n" ); document.write( "Find the term that will complete the square, add to both sides
\n" ); document.write( "Divide the coefficient of x by 2 and square it (5/4)^2 = 25/16
\n" ); document.write( "x^2 + $\"5%2F2\"$ x + $\"25%2F16\"$ = $\"1%2F2\"$ + $\"25%2F16\"$
\n" ); document.write( ":
\n" ); document.write( "x^2 + $\"5%2F2\"$ x + $\"25%2F16\"$ = $\"8%2F16\"$ + $\"25%2F16\"$
\n" ); document.write( ":
\n" ); document.write( "x^2 + $\"5%2F2\"$ x + $\"25%2F16\"$ = $\"33%2F16\"$
\n" ); document.write( ":
\n" ); document.write( "(x + $\"5%2F4\"$ )^2 = $\"33%2F16\"$
\n" ); document.write( ":
\n" ); document.write( "x + $\"5%2F4\"$ = +/- $\"sqrt%2833%2F16%29\"$
\n" ); document.write( "Two solutions
\n" ); document.write( "x = $\"-5%2F4\"$ + $\"1%2F4\"$ $\"sqrt%2833%29\"$
\n" ); document.write( "x = $\"%28-5+%2B+sqrt%2833%29%29%2F4\"$
\n" ); document.write( "and
\n" ); document.write( "x = $\"-5%2F4\"$ - $\"1%2F4\"$ $\"sqrt%2833%29\"$
\n" ); document.write( "x = $\"%28-5+-+sqrt%2833%29%29%2F4\"$
\n" ); document.write( ":
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\n" ); document.write( "The graph
\n" ); document.write( " $\"+graph%28+300%2C+200%2C+-6%2C+5%2C+-10%2C+10%2C+-2x%5E2-5x%2B1%29+\"$ \n" ); document.write( "

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