From e0c6872cf40896c7be36b11dcc744620f10adf1d Mon Sep 17 00:00:00 2001 From: Norbert Preining Date: Mon, 2 Sep 2019 13:46:59 +0900 Subject: Initial commit --- .../latex/contrib/probsoln/samples/prob-easy2.tex | 137 +++++++++++++++++++++ 1 file changed, 137 insertions(+) create mode 100644 macros/latex/contrib/probsoln/samples/prob-easy2.tex (limited to 'macros/latex/contrib/probsoln/samples/prob-easy2.tex') diff --git a/macros/latex/contrib/probsoln/samples/prob-easy2.tex b/macros/latex/contrib/probsoln/samples/prob-easy2.tex new file mode 100644 index 0000000000..d6edc7ee3c --- /dev/null +++ b/macros/latex/contrib/probsoln/samples/prob-easy2.tex @@ -0,0 +1,137 @@ + % This file is public domain + % + % These are all easy differentiation problems + +\begin{defproblem}{diffeasy:gpowh}% +\begin{onlyproblem}% +\(f(x) = g(x)^{h(x)}.\)% +\end{onlyproblem}% +\begin{onlysolution}% +\begin{eqnarray*} +f(x) & = & e^{\ln g(x)^{h(x)}}\\ + & = & e^{h(x)\ln g(x)}\\ +f'(x) & = & e^{h(x)\ln g(x)}(h'(x)\ln g(x) + h(x)\frac{g'(x)}{g(x)})\\ + & = & g(x)^{h(x)}(h'(x)\ln g(x) + \frac{h(x)g'(x)}{g(x)}) +\end{eqnarray*}% +\end{onlysolution}% +\end{defproblem} + +\begin{defproblem}{diffeasy:arcsin}% +\begin{onlyproblem}% +\(y = \arcsin(x)\)% +\end{onlyproblem}% +\begin{onlysolution}% +\[\sin(y) = x\] +diff. w.r.t. $x$: +\begin{eqnarray*} +\cos y \frac{dy}{dx} & = & 1\\ +\frac{dy}{dx} & = & \frac{1}{\cos y}\\ + & = & \frac{1}{\sqrt{1 - \sin^2y}}\\ + & = & \frac{1}{\sqrt{1-x^2}}. +\end{eqnarray*} +\end{onlysolution}% +\end{defproblem} + +\begin{defproblem}{diffeasy:arccos}% +\begin{onlyproblem}% +$y = \arccos x$.% +\end{onlyproblem}% +\begin{onlysolution}% +\(\cos y = x\) +diff. w.r.t. $x$: +\begin{eqnarray*} +-\sin y \frac{dy}{dx} & = & 1\\ +\frac{dy}{dx} & = & \frac{-1}{\sin y}\\ + & = & \frac{-1}{\sqrt{1-\cos^2y}}\\ + & = & \frac{-1}{\sqrt{1-x^2}} +\end{eqnarray*} +\end{onlysolution}% +\end{defproblem} + +\begin{defproblem}{diffeasy:tan}% +\begin{onlyproblem}% +\(y = \tan x\)% +\end{onlyproblem} +\begin{onlysolution}% +\begin{eqnarray*} +y & = & \tan x\\ + & = & \frac{\sin x}{\cos x}\\ +\frac{dy}{dx} & = & \frac{\cos x}{\cos x} + \sin x\times\frac{-1}{\cos^2x}\times -\sin x\\ + & = & 1 + \tan^2x\\ + & = & \sec^2x. +\end{eqnarray*} +\end{onlysolution}% +\end{defproblem} + +\begin{defproblem}{diffeasy:arctan}% +\begin{onlyproblem}% +\(y = \arctan x = \tan^{-1}x\)% +\end{onlyproblem}% +\begin{onlysolution}% +\[\tan y = x\] +diff w.r.t. $x$: +\begin{eqnarray*} +\sec^2y\frac{dy}{dx} & = & 1\\ +\frac{dy}{dx} & = & \frac{1}{\sec^2y}\\ + & = & \frac{1}{1+\tan^2y}\\ + & = & \frac{1}{1+x^2} +\end{eqnarray*} +\end{onlysolution}% +\end{defproblem} + +\begin{defproblem}{diffeasy:cot}% +\begin{onlyproblem}% +\(y = (\tan x)^{-1} = \cot x\)% +\end{onlyproblem} +\begin{onlysolution}% +\begin{eqnarray*} +\frac{dy}{dx} & = & -(\tan x)^{-2}\sec^2x\\ + & = & -\frac{\cos^2x}{\sin^2x}\cdot\frac{1}{\cos^2x}\\ + & = & \frac{-1}{\sin^2x}\\ + & = & -\csc^2x. +\end{eqnarray*} +\end{onlysolution}% +\end{defproblem} + +\begin{defproblem}{diffeasy:cosxsqsinx}% +\begin{onlyproblem}% +$y = \cos(x^2)\sin x$.% +\end{onlyproblem}% +\begin{onlysolution}% +\[\frac{dy}{dx} = -\sin(x^2)2x\sin x + \cos(x^2)\cos x\] +\end{onlysolution}% +\end{defproblem} + +\begin{defproblem}{diffeasy:xlnx}% +\begin{onlyproblem}% +$y = (x+1)\ln(x+1)$. +\end{onlyproblem}% +\begin{onlysolution}% +\begin{eqnarray*} +\frac{dy}{dx} & = & \ln(x+1) + \frac{x+1}{x+1}\\ + & = & 1 + \ln(x+1). +\end{eqnarray*} +\end{onlysolution} +\end{defproblem} + +\begin{defproblem}{diffeasy:glng}% +\begin{onlyproblem}% +$f(x) = g(x)\ln(g(x))$. +\end{onlyproblem} +\begin{onlysolution}% +\begin{eqnarray*} +f'(x) & = & g'(x)\ln(g(x)) + \frac{g(x)}{g(x)}g'(x)\\ + & = & g'(x)(1+\ln(g(x))). +\end{eqnarray*} +\end{onlysolution}% +\end{defproblem} + +\begin{defproblem}{diffeasy:sinx/x} +\begin{onlyproblem}% +$y = \frac{\sin x}{x}$. +\end{onlyproblem} +\begin{onlysolution}% +\[\frac{dy}{dx} = \frac{\cos x}{x} - \frac{\sin x}{x^2}\] +\end{onlysolution}% +\end{defproblem} + -- cgit v1.2.3