You have it selected correctly. 20 is the only option.
Let x =lenght, y = width, and z =height
<span>The volume of the box is equal to V = xyz </span>
<span>Subject to the surface area </span>
<span>S = 2xy + 2xz + 2yz = 64 </span>
<span>= 2(xy + xz + yz) </span>
<span>= 2[xy + x(64/xy) + y(64/xy)] </span>
<span>S(x,y)= 2(xy + 64/y + 64/x) </span>
<span>Then </span>
<span>Mx(x, y) = y = 64/x^2 </span>
<span>My(x, y) = x = 64/y^2 </span>
<span>y^2 = 64/x </span>
<span>(64/x^2)^2 = 64 </span>
<span>4096/x^4 = 64/x </span>
<span>x^3 = 4096/64 </span>
<span>x^3 = 64 </span>
<span>x = 4 </span>
<span>y = 64/x^2 </span>
<span>y = 4 </span>
<span>z= 64/yx </span>
<span>z= 64/16 </span>
<span>z = 4 </span>
<span>Therefor the dimensions are cube 4.</span>
The largest radius for the swimming pool is 15.1 feet
Step-by-step explanation:
Step 1:
Circumference of the circular swimming pool built by Dan = 95 feet
We need to determine the largest radius for the pool.
Step 2 :
Circle's circumference is given by 2πr
Where r represents the radius
This shows that the radius is in direct proportion to the circumference. Hence the radius corresponding to the maximum circumference will be the largest possible radius
So we have 2πr = 95
=> r = 
=> r = 
× 
where 
=> r = 15.1 feet (rounded off to tenth of a foot)
Step 3 :
The largest radius for the swimming pool is 15.1 feet
Answer:
63
Step-by-step explanation:
This is because 25% of 84 is 21. He knows how to play 21 songs. 84-21=63.
63 is how many songs he does NOT know how to play.
