Lagrange multipliers:







(if

)

(if

)

(if

)
In the first octant, we assume

, so we can ignore the caveats above. Now,

so that the only critical point in the region of interest is (1, 2, 2), for which we get a maximum value of

.
We also need to check the boundary of the region, i.e. the intersection of

with the three coordinate axes. But in each case, we would end up setting at least one of the variables to 0, which would force

, so the point we found is the only extremum.
Answer:
I know this is late but the actual answer is d=3s+-50
Step-by-step explanation:
The reason is because he is swimming down, so yeah.
Quotient means division....less then means subtract
(y/2) - 5
Answer:
b. circle; 
Step-by-step explanation:
The given conic has equation;

We complete the square to obtain;

This is a circle with center;

This implies that;

When the circle is rotated through an angle of
,
The new center is obtained using;
and 
We plug in the given angle with x and y values to get;
and 
This gives us;

The equation of the rotated circle is;

Expand;

Multiply through by 4; to get

Write in general form;

Divide through by 2.
