Further Maths - Hyperbolic Functions

2021-03-15
4 min read

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Flashcards

$$\sinh x$$ What is the definition??

$$ \frac{e^x - e^{-x}}{2} $$

$$\cosh x$$ What is the definition??

$$ \frac{e^x + e^{-x}}{2} $$

$$\tanh x$$ What is the definition??

$$ \frac{e^{2x} - 1}{e^{2x} + 1} $$

PHOTO SINH GRAPH What function is this??

$$ \sinh $$

PHOTO COSH GRAPH What function is this??

$$ \cosh $$

PHOTO TANH GRAPH What function is this??

$$ \tanh $$

$$y = \sinh x$$ What does the graph look like??

PHOTO SINH GRAPH

$$y = \cosh x$$ What does the graph look like??

PHOTO COSH GRAPH

$$y = \tanh x$$ What does the graph look like??

PHOTO TANH GRAPH

What is true about any value of $\cosh x$??

It is above $1$.

$$e^x - e^{-x} = 10$$ How would you rewrite this??

$$ e^2x - 1 = 10e^x $$

2021-03-16

$$\arcsinh x$$ What is the definition??

$$ \ln(x + \sqrt{x^2 + 1}) $$

$$\arcosh x$$ What is the definition??

$$ \ln(x + \sqrt{x^2 - 1}) $$

$$\artanh x$$ What is the definition??

$$ \frac{1}{2}\ln\left(\frac{1 + x}{1 - x}\right) $$

What is the domain for $\arcosh x$??

$$ x \ge 1 $$

What is the domain for $\artanh x$??

$$ |x| < 1 $$

PHOTO ARSINH GRAPH What function is this??

$$ \arsinh $$

PHOTO ARCOSH GRAPH What function is this??

$$ \arcosh $$

PHOTO ARTANH GRAPH What function is this??

$$ \artanh $$

$$y = \arsinh x$$ What does the graph look like??

PHOTO ARSINH GRAPH

$$y = \arcosh x$$ What does the graph look like??

PHOTO ARCOSH GRAPH

$$y = \artanh x$$ What does the graph look like??

PHOTO ARTANH GRAPH

What is true about any value of $\cosh x$??

It is above $1$.

2021-03-17

What is Osborn’s Rule??

Replace any product of two $\sin$ terms by minus the products of two $\sin$ terms.

By Osborn’s Rule, what is $\sinA\sinB$ in hyperbolic functions??

$$ -\sinhA\sinhB $$

By Osborn’s Rule, what is $\tan^2 x$ in hyperbolic functions??

$$ -\tanh^2 x $$

How do you convert a trig identity to a hyperbolic trig identity??
  • Replace all normal functions with their hyperbolic equivalents
  • Use Osborn’s Rule
If you’re not allowed to use Osborn’s Rule when converting a hyperbolic trig identity, what can you do??

Use the $e^x$ defintitions of all the functions.

$$\sin^2 x + \cos^2 x = 1$$ What is the hyperbolic equivalent??

$$ \cos^2 x - \sin^2 x = 1 $$

$$\frac{d}{dx} \sinh x$$ What is this equal to??

$$ \cosh x $$

$$\frac{d}{dx} \cosh x$$ What is this equal to??

$$ \sinh x $$

$$\frac{d}{dx} \tanh x$$ What is this equal to??

$$ \sech^2 x $$

$$\frac{d}{dx} (\sinh^{-1} x)$$ What is the equal to??

$$ \frac{1}{\frac{x^2 + 1}} $$

$$\frac{d}{dx} (\cosh^{-1} x)$$ What is the equal to??

$$ \frac{1}{\frac{x^2 - 1}} $$

$$\frac{d}{dx} (\tanh^{-1} x)$$ What is the equal to??

$$ \frac{1}{\frac{1 - x^2}} $$

2021-03-24

If $y = \sinh^{-1}(x)$, what is $x$ equal to??

$$ x = \sinh(y) $$

$$x = \sinh(y)$$ What do you get if you differentiate both sides??

$$ \frac{dx}{dy} = \cosh(y) $$

$$\frac{dx}{dy} = \cosh(y)$$ The aim here is to get $\frac{dy}{dx}$. How could you write $\cosh(y)$ made out of something you already know??

$$ \frac{dx}{dy} = \sqrt{1 + \sinh^2(y)} $$

$$\frac{dx}{dx} = \sqrt{1 + \sinh^2(x)}$$ How could you rewrite this in terms of what you already know??

$$ \frac{dx}{dy} = \sqrt{1 + x^2]} $$

$$\frac{dx}{dy} = u$$ How could you rewrite this so it’s $\frac{dy}{dx}$??

$$ \frac{dy}{dx} = \frac{1}{\sqrt{1 + x^2}} $$

When finding the derivative of an inverse function, what’s the trick??

Rewriting some $f(y)$ in terms of $x$.

2021-03-25

$$\int \frac{1}{\sqrt{x^2 + 1}}dx$$ What is this equal to??

$$ \sinh^{-1} x $$

$$\int \frac{1}{\sqrt{x^2 - 1}}dx$$ What is this equal to??

$$ \cosh^{-1} x $$

$$\frac{d}{dx}\left(\sinh^{-1}\left(\frac{x}{a}\right)\right)$$ What is this equal to??

$$ \frac{1}{\sqrt{x^2 + a^2}} $$

$$\frac{d}{dx}\left(\cosh^{-1}\left(\frac{x}{a}\right)\right)$$ What is this equal to??

$$ \frac{1}{\sqrt{x^2 - a^2}} $$

$$\int\frac{1}{\sqrt{x^2 + a^2}}dx$$ What is this equal to??

$$ \sinh^{-1}\left(\frac{x}{a}\right) \pmb{+ c} $$

$$\int\frac{1}{\sqrt{x^2 - a^2}}dx$$ What is this equal to??

$$ \cosh^{-1}\left(\frac{x}{a}\right) \pmb{+ c} $$

$$\int\frac{1}{\sqrt{x^2 - 16}}dx$$ What is this equal to??

$$ \cosh^{-1}\left(\frac{x}{4}\right) \pmb{+ c} $$

$$\int\frac{1}{\sqrt{x^2 + 8}}dx$$ What is this equal to??

$$ \sinh^{-1}\left(\frac{x}{2\sqrt{2}}\right) \pmb{+ c} $$

$$\sqrt{4x^2 + 1}$$ How could you rewrite this to aid with integrating??

$$ 2\sqrt{x^2 + \frac{1}{2}} $$


Metadata
date: 2021-03-15 12:53
tags:
- '@?further-maths'
- '@?school'
- '@?public'
title: Further Maths - Hyperbolic Functions
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