Thomas' Calculus 13th Edition

Published by Pearson
ISBN 10: 0-32187-896-5
ISBN 13: 978-0-32187-896-0

Chapter 7: Transcendental Functions - Section 7.7 - Hyperbolic Functions - Exercises 7.7 - Page 430: 3

Answer

$\sinh x=\dfrac{8}{15}\\ \cosh x= \dfrac{17}{15} ;\\ \tanh x= \dfrac{8}{17} ;\\ sech x=\dfrac{15}{17}; \\ csch x=\dfrac{15}{8}$ and $ coth x=\dfrac{17}{8}$

Work Step by Step

Given: $\cosh x=\dfrac{17}{15}$ The remaining hyperbolic functions can be found as follows: Use the fact:$\cosh^2 x-\sinh^2x=1$ or, $(\dfrac{17}{15})^2-\sinh^2 x=1 $ or, $ \sinh^2 x=\dfrac{64}{225}$ Thus, $\sinh x= \dfrac{8}{15}$ $\tanh x= \dfrac{\sin hx}{\cosh x}=\dfrac{\dfrac{8}{15}}{\dfrac{17}{15}}=\dfrac{8}{17}$ Now, $sech x= \dfrac{1}{\cosh x}=\dfrac{1}{\dfrac{17}{15}}=\dfrac{15}{17} \\ csch x= \dfrac{1}{\sinh x}=\dfrac{1}{\dfrac{8}{15}}=\dfrac{15}{8}$ and $coth x= \dfrac{1}{\tanh x}=\dfrac{1}{\dfrac{8}{17}}=\dfrac{17}{8}$
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.