5a^2 - 6a -4 - (<span>-7a^2 + 3a -9)
=</span>5a^2 - 6a -4 + 7a^2 - 3a + 9
=12a^2 - 9a + 5
answer
12a^2 - 9a + 5
Cost of Car= C
$19,028 <span>≥</span><span> C ≤ $370,790
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The cost of the sports car is greater than or equal to $19, 028 and less than or equal to $370,790.
The answer is c
1/6 divided by 1/2
i had this question on my own
The height of the cone is 8.59
F(x) = 18-x^2 is a parabola having vertex at (0, 18) and opening downwards.
g(x) = 2x^2-9 is a parabola having vertex at (0, -9) and opening upwards.
By symmetry, let the x-coordinates of the vertices of rectangle be x and -x => its width is 2x.
Height of the rectangle is y1 + y2, where y1 is the y-coordinate of the vertex on the parabola f and y2 is that of g.
=> Area, A
= 2x (y1 - y2)
= 2x (18 - x^2 - 2x^2 + 9)
= 2x (27 - 3x^2)
= 54x - 6x^3
For area to be maximum, dA/dx = 0 and d²A/dx² < 0
=> 54 - 18x^2 = 0
=> x = √3 (note: x = - √3 gives the x-coordinate of vertex in second and third quadrants)
d²A/dx² = - 36x < 0 for x = √3
=> maximum area
= 54(√3) - 6(√3)^3
= 54√3 - 18√3
= 36√3.
