## anonymous 5 years ago Electrical wires suspended between two towers form a catenary (see figure) modeled by the equation shown below, where x and y are measured in meters. (see attachment)

1. anonymous

This is the full question.

2. anonymous

the length has to be greater than 40 but less than 60 i will try finding an exact value

3. anonymous

its somewhere around 45 i dont know how to solve cosh so im using approximation

4. anonymous

I think cosh is just an expression, because I used microsoft math and it said that the derivative was sinh

5. anonymous

I found it to be 44.956, but the online system says that is wrong. But I think I am close

6. anonymous

I found this for cosh: http://www.ucl.ac.uk/Mathematics/geomath/level2/hyper/diff11.gif

7. anonymous

ive heard of it but i cant operate using it i can work with sin and cos

8. anonymous

$\int\limits_{-20}^{20}\sqrt(1 + (\sinh(x/20))^2) dx$

9. anonymous

hello!

10. amistre64

as long as you are using the dervivative of the cosh that should work, plug it into wolframalpha.com to get an exact anwer to that :) int(sqrt(......))dx from a to b

11. anonymous

is this the right equation?

12. amistre64

if the question is find the length of the wire; than yes; but try it finding only the right side, and then double it

13. anonymous

okay. I tried putting it in wolfram alpha, and it gives me 47.008, and it works. Thanks

14. amistre64

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