document.write( "Question 164163: The number of tickets sold each day for an upcoming performance of Handel's Messiah is given by N(x)=-0.4x^2+8x+12, 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 #120987 by aka042(26)\"\" \"About 
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The ticket sales peak at the equations vertex (the highest point of the quadratic equation). The x value of the vertex can be found by the equation \"-b%2F%282%2Aa%29\". Your b is the coefficient of x, which is 8, and a is the coefficient of x^2, which is -.4. Therefore the x value of the vertex is \"-8%2F%282%2A-.4%29+=+-8%2F-.8+=+10\". Since your x value is the number of days, then we know daily ticket sales peak at 10 days.
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\n" ); document.write( "To find the number of tickets sold that day, we simply plug 10 into your equation. So . Therefore ticket sales peak at day 10, and 52 tickets will be sold that day. \n" ); document.write( "
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