9514 1404 393
Answer:
   65.52 square feet
Step-by-step explanation:
The area of a rhombus is half the product of the diagonals.
   A = (1/2)ab
   A = (1/2)(12.6 ft)(10.4 ft) = 65.52 ft²
The area of the farm is 65.52 square feet.
 
        
             
        
        
        
Tracking a change over time.
        
                    
             
        
        
        
F(x)=2x²+18x+16
1) we have to calculate the first derived.
f´(x)=4x+18
2) Now, we equalize the first derived to "0" and find out the value of "x"
4x+18=0
4x=-18
x=-18/4=-4.5
3)we calculate the second derived 
f´´(x)=4>0  ⇒we have a minimum at x=-4.5
4) Now we calculate the value of "y".
f(-4.5)=2(-4.5)²+18(-4.5)+16=40.5-81+16=-24.5
Therefore; Exist a minimum at (-4.5 , -24.5)