# differentiating a hyperbolic function

• May 18th 2009, 11:34 AM
djmccabie
differentiating a hyperbolic function
assuming the derivatives of $\displaystyle sinh\theta$ and $\displaystyle cosh\theta$, use the quotient rule to find the derivative of $\displaystyle coth\theta$

I have no idea how to start this because i dont know what the derivatives are :S
• May 18th 2009, 01:18 PM
craig
Quote:

Originally Posted by djmccabie
assuming the derivatives of $\displaystyle sinh\theta$ and $\displaystyle cosh\theta$, use the quotient rule to find the derivative of $\displaystyle coth\theta$

I have no idea how to start this because i dont know what the derivatives are :S

The derivatives of sinh and cosh are very similar to their sin and cos counterparts. They are in fact easier, sinh differentiates to cosh, and cosh differentiates to sinh, you do not have to worry about any minus signs.

As for the quotient rule, here is a link that explains it well.

Quotient Rule -- from Wolfram MathWorld

Hope this helps.
• May 18th 2009, 01:20 PM
djmccabie
thanks i know the quotient rule, so am i just prooving coth ?
• May 18th 2009, 01:22 PM
craig
Quote:

Originally Posted by djmccabie
thanks i know the quotient rule, so am i just prooving coth ?

Yes just use the quotient rule and the derivatives to prove coth :)