document.write( "Question 482759: The number of tickets sold each day for an upcoming performance of Handels Messiah is given by N(x)=-0.4x^2+12x+15 where x is the number of days since the concert was first announced. When will daily ticket sales peak and how many tickets will be sold that day? \n" ); document.write( "

Algebra.Com's Answer #330421 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
When a quadratic has the general form
\n" ); document.write( " $\"+f%28x%29+=++ax%5E2+%2B+bx+%2B+c++\"$ , the peak is at $\"x+=++-b%2F%282a%29+\"$ .
\n" ); document.write( "when $\"+a+\"$ is a negative number.
\n" ); document.write( "given:
\n" ); document.write( " $\"+N%28x%29=+-.4x%5E2%2B12x%2B15+\"$
\n" ); document.write( " $\"x\"$ max = $\"-b%2F%282a%29+\"$
\n" ); document.write( " $\"+-b%2F%282a%29+=+-12%2F%282%2A%28-.4%29%29+\"$
\n" ); document.write( " $\"+-b%2F%282a%29+=+12%2F.8+\"$
\n" ); document.write( " $\"+-b%2F%282a%29+=+15+\"$
\n" ); document.write( "daily ticket sales will peak 15 days after concert was announced
\n" ); document.write( "The number of tickets sold on that day will be
\n" ); document.write( " $\"+N%2815%29=+-.4%2A15%5E2%2B12%2A15%2B15+\"$
\n" ); document.write( " $\"+N%2815%29=+-90+%2B+180+%2B+15+\"$
\n" ); document.write( " $\"+N%2815%29+=+105+\"$
\n" ); document.write( "---------------
\n" ); document.write( "You can check this by making sure that both
\n" ); document.write( " $\"+N%2814%29\"$ and $\"N%2816%29\"$ are smaller than $\"+105+\"$ \n" ); document.write( "

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