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anonymous
 one year ago
At where does y=54x 9x^2 have a maximum value? Using calc, pls...?
anonymous
 one year ago
At where does y=54x 9x^2 have a maximum value? Using calc, pls...?

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0take the y' and the let the equation = 0 then solve it

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0y'=5418x y'=5418x=0 solve for x x=54/18=3

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0now use this value (3) in y=54x 9x^2 y=54(3)9(3)^2 =16281=81 (3,81)

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.0alternatively, we note that the graph of your function is a parabola like this: dw:1433063023555:dw whose xcoordinate of vertex is: \[\Large {x_V} =  \frac{b}{{2a}} =  \frac{{54}}{{2\left( {  9} \right)}} = ...?\] and the ycoordinate of the vertex, is: \[\Large {y_V} =  \frac{{{b^2}  4ac}}{{4a}} =  \frac{{{{54}^2}}}{{4\left( {  9} \right)}} = ...?\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0@AJ01 and @michele_laino Thanks a bunch, it means a lot :')
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