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: 32

Answer

$-\displaystyle \frac{x\cdot{\rm sech}^{-1}x}{\sqrt{1-x^{2}}}$

Work Step by Step

$y=\ln x+(1-x^{2})^{1/2}{\rm sech}^{-1}x$ $\displaystyle \frac{d}{dx}[\ln x]=\frac{1}{x}$ $\displaystyle \frac{d}{dx}[(1-x^{2})^{1/2}]$ Apply the chain rule: $=\displaystyle \frac{1}{2}\cdot(1-x^{2})^{-1/2}\cdot(-2x)=\frac{-x}{\sqrt{1-x^{2}}}$ $\displaystyle \frac{d}{dx}[{\rm sech}^{-1}x]=\frac{-1}{x\sqrt{1-x^{2}}}\quad$ ... (table 10) Applying the sum and product rules of differentiation $\displaystyle \frac{dy}{dx}=\\\frac{d}{dx}[\ln x]+(1-x^{2})^{1/2}\cdot\frac{d}{dx}[{\rm sech}^{-1}x]+\frac{d}{dx}[(1-x^{2})^{1/2}]\cdot{\rm sech}^{-1}x$ $=\displaystyle \frac{1}{x}+(1-x^{2})^{1/2}(\frac{-1}{x\sqrt{1-x^{2}}})-\frac{x}{\sqrt{1-x^{2}}}\cdot{\rm sech}^{-1}x$ $=\displaystyle \frac{1}{x}-\frac{1}{x}-\frac{x{\rm sech}^{-1}x}{\sqrt{1-x^{2}}}$ = $-\displaystyle \frac{x{\rm sech}^{-1}x}{\sqrt{1-x^{2}}}$
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.