document.write( "Question 542429: Determine the quadratic function,F(x)=a^2+bx+c , whose vertex is (3, 7) and passes through the point (5, -9). \n" ); document.write( "

Algebra.Com's Answer #354566 by KMST(5328) $\"\"$ $\"About$

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A quadratic functions whose vertex is (3,7) can be written (in vertex form) as
\n" ); document.write( " $\"f%28x%29=a%28x-3%29%5E2%2B7\"$
\n" ); document.write( "If it passes through (5,-9), $\"f%285%29=-9\"$ , so
\n" ); document.write( " $\"a%285-3%29%5E2%2B7=-9\"$ --> $\"4a%2B7=-9\"$ --> $\"4a=-16\"$ --> $\"a=-4\"$
\n" ); document.write( " $\"f%28x%29=-4%28x-3%29%5E2%2B7\"$ <---> $\"f%28x%29=-4x%5E2%2B24x-29\"$ \n" ); document.write( "

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