Hi, I have 2 questions on these words problems. I really am not sure where to start these.
1. An advertisement consists of a rectangular printed region with margins of 2 inches each at the top and bottom and 1 inch at each side. If the area of the printed region is to be 98 in^2 , find the overall dimensions if the total area of the advertisement is to be a minimum.
2. A rancher is going to build a 3-sided enclosure with a divider down the middle. The cost per foot of the 3 side walls are $6/ft, with the single back wall being $10/ft. The area enclosed will be 180 ft^2. What dimensions would minimize the cost?
The pen looks like this.
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for this one I had an idea of setting 180ft^2 = 3y+x but am not sure if this is the right way to start.
Thanks for the advice on both of the questions, for this one would it then end up being,
x=b y=l
not sure how to get [tex] to work for this one, but
-392(y-4)^-2 = -2
(y-4)^-2 = 196
take the -2 root of each side
y-4 = - 14
y = -10
then when I find x I get -5
I dont think these should be negative though?
There is not such thing as -2 root. You should apply the cross product rule:a/b=c/d is equivalent to a*d=b*c.
therefore, (y-4)^-2=196 becomes (y-4)^2=1/196 and now apply the square root to find
y-4=1/14 or -1/14
So, your solutions are y=4+1/14 and y=4-1/14, both positive.