# Math Help - hyperbolic assignment question

1. ## hyperbolic assignment question

Hi all, Im having trouble with this question:

A chain hangs so that its shape is of the form y=56ch(x/56).
Determine correct to 4 SF

a) the value of y when x is 35

I simply plugged this into the calculator and got the answer 67.29

and

b) the value of x when y is 65.

Im not sure how i rearrange the equation or what to do really at all.

Thanks, Dan

2. Originally Posted by danieljamie
Hi all, Im having trouble with this question:

A chain hangs so that its shape is of the form y=56ch(x/56).
Determine correct to 4 SF

a) the value of y when x is 35

I simply plugged this into the calculator and got the answer 67.29

and

b) the value of x when y is 65.

Im not sure how i rearrange the equation or what to do really at all.

Thanks, Dan
Does your calculator have a $ch^{-1}$ button (I assume by ch you mean cosh ....?)

If not, then you will first need to substitute the definition for ch (the one with the exponentials - can you do this? Please show your work).

3. ## calculator

Yes I do have the $ch^{-1}$ button, but I am not sure how i rearrange the equation to find out what X is. How can I find X by using inverse cosh when it is X/56? Thanks, Dan

4. Originally Posted by danieljamie
Yes I do have the $ch^{-1}$ button, but I am not sure how i rearrange the equation to find out what X is. How can I find X by using inverse cosh when it is X/56? Thanks, Dan
65 = 56 ch(x/56)

=> 65/56 = ch(x/56)

=> ch^{-1} (65/56) = x/56

=> x = 56 ch^{-1} (65/56) = ....

5. Thankyou very much! Now I can get ahead in my assignments!

Daniel