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) 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( " \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( " \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( " \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( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \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( " |