Answer:
- 12 ft parallel to the river
- 6 ft perpendicular to the river
Step-by-step explanation:
The least fence is used when half the total fence is parallel to the river. That is, the shape of the rectangle is twice as long as it is wide.
72 = W(2W)
36 = W²
6 = W . . . . . . the width perpendicular to the river
12 = 2W . . . . the length parallel to the river
_____
<em>Development of this relation</em>
Let T represent the total length of the fence for some area A. Then if x is the length along the river, the width is y=(T-x)/2, and the area is ...
A = xy = x(T -x)/2
Note that the equation for area is that of a parabola with zeros at x=0 and at x=T. That is, for some fence length T, the area will be a maximum at the vertex of this parabola. That vertex is located halfway between the zeros, at ...
x = (0 +T)/2 = T/2
The corresponding area width (y) is ...
y = (T -T/2)/2 = T/4
Equivalently, the fence length T will be a minimum for some area A when x=T/2 and y=T/4. This is the result we used above.
Option B: 
is the correct answer.
Explanation:
The exponential equation is 
If 
, then 
Thus, the equation becomes
Applying log rule, 
and thus the equation becomes
Since, we know that, 
, using this we get,
Hence, the logarithmic equation which is equivalent to the exponential equation is
Thus, Option B is the correct answer.
D
Absolute Value of a number is the positive of whatever to total value is. For example |-12| = 12, and |32| = 32
Integer means a whole number , a number that is not fraction
Katie did not specifically said what numbers , the numbers can be fraction and it would not be called integer so that is Katie's error
We know that
see the picture to better understand the problem
in the right triangle ABC
Applying the Pythagoras Theorem
AB²=BC²+AC²-------> BC²=AB²-AC²
AB=8 ft
AC=4 ft
BC²=8²-4²-----> BC²=48--------> BC=√48-------> BC=6.93 ft
the answer is6.93 ft
