document.write( "Question 618720: for the quadratic equation -16t^2+125t what is the maximum and minimum? \n" ); document.write( "
Algebra.Com's Answer #389063 by math-vortex(648)\"\" \"About 
You can put this solution on YOUR website!
Hi, there--
\n" ); document.write( ".
\n" ); document.write( "A quadratic equation only has one, either a maximum or a minimum. It won't have both.
\n" ); document.write( ".
\n" ); document.write( "The shape of the graph of a quadratic is a parabola. If the parabola opens upward, the the equation has a minimum at the vertex. If the parabola opens downward, the equation has a maximum at the vertex.
\n" ); document.write( ".
\n" ); document.write( "There are many ways to solve this problem. I'm not sure what math level you are studying, so I'll show an Algebra I method.
\n" ); document.write( ".
\n" ); document.write( "Since the minimum or maximum is located at the vertex, we'll end the vertex of this equation. The vertex will be an ordered pair (t,h). We have
\n" ); document.write( ".
\n" ); document.write( "\"h=-16t%5E2%2B125t\"
\n" ); document.write( ".
\n" ); document.write( "Notice that I added an h to be the 2nd variable of the equation. You could use any variable. When a quadratic equation is in standard form,
\n" ); document.write( ".
\n" ); document.write( "\"h=at%5E2%2Bbt%2Bc\"
\n" ); document.write( ".
\n" ); document.write( "the t-value of the vertex is the value -b/2a, where a and b are the coefficients of the t^2 term and the t term in your equation. In your case a=-16 and b=125. Therefore,
\n" ); document.write( ".
\n" ); document.write( "\"-b%2F2a=%28-125%29%2F%282%2A-16%29=125%2F32\"
\n" ); document.write( ".
\n" ); document.write( "So the t-value of the vertex is 125/32. To find the h-value, we use substitution:
\n" ); document.write( ".
\n" ); document.write( "\"h=-16%28125%2F32%29%5E2%2B125%28125%2F32%29\"
\n" ); document.write( "\"h=-250000%2F1024%2B15625%2F32\"
\n" ); document.write( "\"h=-250000%2F1024%2B500000%2F1024\"
\n" ); document.write( "\"h=250000%2F1024=15625%2F64\"
\n" ); document.write( ".
\n" ); document.write( "Now we know that the vertex of the parabola is at the point (125/32, 15625/64).
\n" ); document.write( ".
\n" ); document.write( "When a quadratic equation is in standard form, we can use the leading coefficient---the a-value---to determine if the parabola opens upward or downward. If a>0, the parabola opens up; if a<0, it opens down. In your case the parabola opens downward. This means that the vertex is a maximum for your parabola.
\n" ); document.write( ".
\n" ); document.write( "Hope this helps. Feel free to email if you have questions about this.
\n" ); document.write( ".
\n" ); document.write( "Ms.Figgy
\n" ); document.write( "math.in.the.vortex@gmail.com\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );