document.write( "Question 1111544: What is the vertex of the parabola f(x)=-2(x-7)^2-4?? \n" ); document.write( "

Algebra.Com's Answer #726540 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"+f%28x%29+=+-2%2A%28+x-7+%29%5E2+-+4+\"$
\n" ); document.write( " $\"+f%28x%29+=+-2%2A%28+x%5E2+-+14x+%2B+49+%29+-+4+\"$
\n" ); document.write( " $\"+f%28x%29+=+-2x%5E2+%2B+28x+-+98+-+4+\"$
\n" ); document.write( " $\"+f%28x%29+=+-2x%5E2+%2B+28x+-+102+\"$
\n" ); document.write( "-------------------------------------
\n" ); document.write( "The formula for the x-value of the vertex is:
\n" ); document.write( " $\"+x%5Bv%5D+=+-b%2F%282a%29+\"$
\n" ); document.write( "when the form is:
\n" ); document.write( " $\"+f%28x%29+=+a%2Ax%5E2+%2B+b%2Ax+%2B+c+\"$
\n" ); document.write( "----------------------------------
\n" ); document.write( " $\"+x%5Bv%5D+=+-28%2F%282%2A%28-2%29+%29+\"$
\n" ); document.write( " $\"+x%5Bv%5D+=+7+\"$
\n" ); document.write( "Plug this result back into the equation
\n" ); document.write( " $\"+f%287%29+=+-2%2A7%5E2+%2B+28%2A7+-+102+\"$
\n" ); document.write( " $\"+f%287%29+=+-98+%2B+196+-+102+\"$
\n" ); document.write( " $\"+f%287%29+=+-4+\"$
\n" ); document.write( "The vertex is at ( 7, -4 )
\n" ); document.write( "------------------------------------
\n" ); document.write( "check:
\n" ); document.write( "Here's the plot:
\n" ); document.write( " $\"+graph%28+400%2C+400%2C+-5%2C+10%2C+-20%2C+2%2C+-2x%5E2+%2B+28x+-+102+%29+\"$
\n" ); document.write( "Looks correct \n" ); document.write( "

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