Need someone to check my work:

Find the dimensions for the rectangle of largest area which has its base on the x-axis and its top two vertices on the graph of the following function

4/(5+x^2)

I set A=2xy
so 2x(4/(5+x^2))
Then I derived everything and found the zero to be sqrt(5) and the answer to be:
(sqrt(5),2/5)

Question

Need someone to check my work:

Find the dimensions for the rectangle of largest area which has its base on the x-axis and its top two vertices on the graph of the following function

4/(5+x^2)

I set A=2xy
so 2x(4/(5+x^2))
Then I derived everything and found the zero to be sqrt(5) and the answer to be:
(sqrt(5),2/5)

dape · Answer

Everything is fine, except that you used $2x$ for the base of the rectangle, so the dimensions for $x$ should have a factor 2. So the dimensions for the rectangle should be $2\sqrt{5}\times\frac{2}{5}$.

dape · Answer

the x is not times, in your notation it's $(2\sqrt{5},2/5)$

anonymous · Answer

Thanks! Some minor errors on my part that i should've caught! Was thinking it said coordinates. Thanks for your help,really appreciate it

dape · Answer

No problem, glad I could be of help.