Answer:
noted, thanks for the note
 
        
                    
             
        
        
        
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. 
        
             
        
        
        
44,000
38,720
34,073.60
29,984.77
26,386.60
        
             
        
        
        
Answer:
39.5
Step-by-step explanation:
angle ABC=60=(5x+2)+(3x-2)
60=8x
x=7.5
Angle ABD=(5x+2),(sub x=7.5)
                   =(5*7.5+2)
                   =39.5
 
        
             
        
        
        
D. Size and shape. Congruent essentially means that they’re the same in all ways.