When a line and a curve are tangent to each other, they are joined together by 1 point (x,y). So, you equate both equations either in terms of x or y. For this problem, let's equate in terms of y.
y = k - x
y = x² + 3x + 1
k - x = x² + 3x + 1
k = x² + 3x + x + 1
k = x² + 4x + 1
This would be the value of k. Since we are not given the common point, it can only be expressed in terms of x or y.
The formula for an area of a regular parallelogram is:
A = l * w
Where,
l = length
w = width
We are given that the total measurement of fence is only
60 feet and one side of the house is used as one side of the pen. Therefore,
l + 2 w = 60
<span>or simplifying to make an explicit expression for
one variable, say l:</span>
l = 60 – 2 w
<span>Substituting to the 1st equation:</span>
A = (60 – 2 w) * w
A = 60 w – 2 w^2
<span>The maxima are obtained by getting the 1st
derivative then equating dA/dw = 0:</span>
dA/dw
= 60 – 4 w
60 –
4 w = 0
4 w
= 60
w =
15
Since
l = 60 - 2w
l =
60 – 30
l =
30
<span>Therefore
the dimension that will make the largest pen is 15 ft by 30 ft.</span>
<span>ANSWER: C</span>
Answer:
(x/5) - 4
Step-by-step explanation:
You want four less than the quotient of x and 5 so you make x/5 a single term. Then subtract 4