Answer:
B
Step-by-step explanation:
Hope this helps! have a great day!
 
        
             
        
        
        
Answer:
13.4±2.132(1.02/5)
Step-by-step explanation:
Khan Academy
 
        
             
        
        
        
The formula for the radius r in terms of x . and for the maximum areas is x=2/ +4
+4
Given that,
y forms a circle of radius r
y=2 r
r
r=y/2
(2-y)- forms Square Side x
(2-y) = 4x
x=(2-y)/4
Now Sum of Area's=Area of Square +Area of Circle 
Sum =  r² + x²
r² + x²
Substitute the r and x values in above equation,
A(y)= y²/4 +(y-2)²/ 16
+(y-2)²/ 16
To maximize Area A(y)
A'(y)= 0
2y/4 + 2(y-2)/16 =0
 + 2(y-2)/16 =0
y/2 + (y-2)/8 =0
 + (y-2)/8 =0
y = 2 /
/ +4
+4
Y max will be max, x to be maximum.
for maximum sum of areas,
x=2/ +4
+4
Hence,The formula for the radius r in terms of x . and for the maximum areas is x=2/ +4
+4
Learn more about Area :
brainly.com/question/28642423
#SPJ4
 
        
             
        
        
        
Answer:
18
Step-by-step explanation:
81π=πr^2
r= 9,-9
9+9=18