% Created by datatooltk on Thu Jun 26 15:43:38 BST 2014 \DTLifdbexists{mth102}% {\PackageError{datatool}{Database `mth102' already exists}{}% \aftergroup\endinput}{}% \bgroup\makeatletter \dtl@message{Reconstructing database `mth102'}% \expandafter\global\expandafter \newtoks\csname dtlkeys@mth102\endcsname \expandafter\global \csname dtlkeys@mth102\endcsname={% % % header block for column 1 \db@plist@elt@w % \db@col@id@w 1% \db@col@id@end@ % \db@key@id@w Label% \db@key@id@end@ % \db@type@id@w 0% \db@type@id@end@ % \db@header@id@w Label% \db@header@id@end@ % \db@col@id@w 1% \db@col@id@end@ % \db@plist@elt@end@ % % header block for column 2 \db@plist@elt@w % \db@col@id@w 2% \db@col@id@end@ % \db@key@id@w Question% \db@key@id@end@ % \db@type@id@w 0% \db@type@id@end@ % \db@header@id@w Question% \db@header@id@end@ % \db@col@id@w 2% \db@col@id@end@ % \db@plist@elt@end@ % % header block for column 3 \db@plist@elt@w % \db@col@id@w 3% \db@col@id@end@ % \db@key@id@w Answer% \db@key@id@end@ % \db@type@id@w 0% \db@type@id@end@ % \db@header@id@w Answer% \db@header@id@end@ % \db@col@id@w 3% \db@col@id@end@ % \db@plist@elt@end@ % % header block for column 4 \db@plist@elt@w % \db@col@id@w 4% \db@col@id@end@ % \db@key@id@w Level% \db@key@id@end@ % \db@type@id@w 1% \db@type@id@end@ % \db@header@id@w Level% \db@header@id@end@ % \db@col@id@w 4% \db@col@id@end@ % \db@plist@elt@end@ % % header block for column 5 \db@plist@elt@w % \db@col@id@w 5% \db@col@id@end@ % \db@key@id@w Topic% \db@key@id@end@ % \db@type@id@w 0% \db@type@id@end@ % \db@header@id@w Topic% \db@header@id@end@ % \db@col@id@w 5% \db@col@id@end@ % \db@plist@elt@end@ % }% \expandafter\global\expandafter \newtoks\csname dtldb@mth102\endcsname \expandafter\global \csname dtldb@mth102\endcsname={% % % Start of row 1 \db@row@elt@w % \db@row@id@w 1% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w diff:gpowh% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w \(f(x) = g(x)^{h(x)}.\)% \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \begin{align*} f(x) & = e^{\ln g(x)^{h(x)}}\\ & = e^{h(x)\ln g(x)}\\ f'(x) & = e^{h(x)\ln g(x)}\left(h'(x)\ln g(x) + h(x)\frac {g'(x)}{g(x)}\right)\\ & = g(x)^{h(x)}\left(h'(x)\ln g(x) + \frac {h(x)g'(x)}{g(x)}\right) \end{align*}% \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 3% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Basic% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 1 \db@row@id@w 1% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 2 \db@row@elt@w % \db@row@id@w 2% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w diff:arcsin% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w \(y = \arcsin (x)\)% \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \[\sin (y) = x\] diff. w.r.t. $x$: \begin{align*} \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{align*} % \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 2% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Basic% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 2 \db@row@id@w 2% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 3 \db@row@elt@w % \db@row@id@w 3% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w diff:arccos% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w $y = \arccos x$.% \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \(\cos y = x\) diff. w.r.t. $x$: \begin{align*} -\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{align*} % \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 2% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Basic% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 3 \db@row@id@w 3% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 4 \db@row@elt@w % \db@row@id@w 4% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w diff:tan% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w \(y = \tan x\) % \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \begin{align*} 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{align*} % \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 2% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Basic% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 4 \db@row@id@w 4% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 5 \db@row@elt@w % \db@row@id@w 5% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w diff:arctan% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w \(y = \arctan x = \tan ^{-1}x\)% \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \[\tan y = x\] diff w.r.t. $x$: \begin{align*} \sec ^2y\frac {dy}{dx} & = 1\\ \frac {dy}{dx} & = \frac {1}{\sec ^2y}\\ & = \frac {1}{1+\tan ^2y}\\ & = \frac {1}{1+x^2} \end{align*} % \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 3% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Basic% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 5 \db@row@id@w 5% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 6 \db@row@elt@w % \db@row@id@w 6% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w diff:cot% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w \(y = (\tan x)^{-1} = \cot x\) % \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \begin{align*} \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{align*} % \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 2% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Basic% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 6 \db@row@id@w 6% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 7 \db@row@elt@w % \db@row@id@w 7% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w diff:cosxsqsinx% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w $y = \cos (x^2)\sin x$.% \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \[ \frac {dy}{dx} = -\sin (x^2)2x\sin x + \cos (x^2)\cos x \] % \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 2% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Basic% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 7 \db@row@id@w 7% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 8 \db@row@elt@w % \db@row@id@w 8% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w diff:xlnx% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w $y = (x+1)\ln (x+1)$. % \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \begin{align*} \frac{dy}{dx} & = \ln(x+1) + \frac{x+1}{x+1}\\ & = 1 + \ln(x+1). \end{align*} % \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 1% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Basic% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 8 \db@row@id@w 8% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 9 \db@row@elt@w % \db@row@id@w 9% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w diff:glng% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w $f(x) = g(x)\ln (g(x))$. % \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \begin{align*} f'(x) & = g'(x)\ln(g(x)) + \frac{g(x)}{g(x)}g'(x)\\ & = g'(x)(1+\ln(g(x))). \end{align*} % \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 1% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Basic% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 9 \db@row@id@w 9% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 10 \db@row@elt@w % \db@row@id@w 10% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w diff:sinx/x% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w $y = \frac {\sin x}{x}$. % \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \[ \frac{dy}{dx} = \frac{\cos x}{x} - \frac{\sin x}{x^2} \]% \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 1% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Basic% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 10 \db@row@id@w 10% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 11 \db@row@elt@w % \db@row@id@w 11% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w dfp:xcube% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w Differentiate $f(x) = x^3$ with respect to $x$ by first principles.% \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \begin {align*} \frac {dy}{dx} & = \lim _{\Delta x\rightarrow 0}\frac {f(x+\Delta x) - f(x)}{\Delta x}\\ & = \lim _{\Delta x\rightarrow 0}\frac {(x+\Delta x)^3-x^3}{\Delta x}\\ & = \lim _{\Delta x\rightarrow 0}\frac {(x+\Delta x)(x^2+2x\Delta x+(\Delta x)^2)-x^3}{\Delta x}\\ & = \lim _{\Delta x\rightarrow 0}\frac {x^3+3x^2\Delta x+3x(\Delta x)^2+(\Delta x)^3-x^3}{\Delta x}\\ & = \lim _{\Delta x\rightarrow 0}\frac {3x^2\Delta x+3x(\Delta x)^2+(\Delta x)^3}{\Delta x}\\ & = \lim _{\Delta x\rightarrow 0}3x^2+3x\Delta x + (\Delta x)^2\\ & = 3x^2 \end {align*}% \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 3% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Theory% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 11 \db@row@id@w 11% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 12 \db@row@elt@w % \db@row@id@w 12% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w dfp:Ioverxsq% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w Differentiate $\displaystyle f(x) = \frac {1}{x^2}$ with respect to $x$ by first principles.% \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \begin {align*} \frac {df}{dx} & = \lim _{\Delta x\rightarrow 0}\frac {\frac {1}{(x+\Delta x)^2}-\frac {1}{x^2}}{\Delta x}\\ & = \lim _{\Delta x\rightarrow 0}\frac {\frac {x^2-(x+\Delta x)^2}{x^2(x+\Delta x)^2}}{\Delta x}\\ & = \lim _{\Delta x\rightarrow 0}\frac {x^2-(x^2+2x\Delta x+(\Delta x)^2)}{x^2\Delta x(x+\Delta x)^2}\\ & = \lim _{\Delta x\rightarrow 0}\frac {-2x\Delta x-(\Delta x)^2}{x^2\Delta x(x+\Delta x)^2}\\ & = \lim _{\Delta x\rightarrow 0}\frac {-2x-\Delta x}{x^2(x+\Delta x)^2}\\ & = \frac {-2x}{x^2x^2}\\ & = -\frac {2}{x^3} \end {align*}% \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 3% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Theory% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 12 \db@row@id@w 12% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 13 \db@row@elt@w % \db@row@id@w 13% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w dfp:sqrtx% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w Differentiate from first principles $f(x) = \surd x$% \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \begin {align*} \frac {df}{dx} & = \lim _{\Delta x\rightarrow 0}\frac {\sqrt {x+\Delta x}-\surd x}{\Delta x}\\ & = \lim _{\Delta x\rightarrow 0}\frac {(\sqrt {x+\Delta x}-\surd x)(\sqrt {x+\delta x}+\surd x)}{\Delta x(\sqrt {x+\Delta x}+\surd x)}\\ & = \lim _{\Delta x\rightarrow 0}\frac {x+\Delta x - x}{\Delta x(\sqrt {x+\Delta x}+\surd x)}\\ & = \lim _{\Delta x\rightarrow 0}\frac {\Delta x}{\Delta x(\sqrt {x+\Delta x}+\Delta x)}\\ & = \lim _{\Delta x\rightarrow 0}\frac {1}{\sqrt {x+\Delta x}+\surd x}\\ & = \frac {1}{2\surd x} \end {align*}% \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 3% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Theory% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 13 \db@row@id@w 13% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 14 \db@row@elt@w % \db@row@id@w 14% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w dfp:cons% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w Differentiate from first principles $f(x) = c$ where $c$ is a constant.% \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \begin {align*} \frac {df}{dx} & = \lim _{\Delta x\rightarrow 0}\frac {c-c}{\Delta x}\\ & = \lim _{\Delta x\rightarrow 0}0\\ & = 0 \end {align*}% \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 3% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Theory% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 14 \db@row@id@w 14% \db@row@id@end@ % \db@row@elt@end@ % % Start of row 15 \db@row@elt@w % \db@row@id@w 15% \db@row@id@end@ % % Column 1 \db@col@id@w 1% \db@col@id@end@ % \db@col@elt@w dfp:cosx% \db@col@elt@end@ % \db@col@id@w 1% \db@col@id@end@ % % Column 2 \db@col@id@w 2% \db@col@id@end@ % \db@col@elt@w Given \begin {align*} \lim _{x \rightarrow 0} \frac {\cos x - 1}{x} & = 0\\ \lim _{x \rightarrow 0} \frac {\sin x}{x} & = 1 \end {align*} differentiate from first principles $f(x) = \cos x$.% \db@col@elt@end@ % \db@col@id@w 2% \db@col@id@end@ % % Column 3 \db@col@id@w 3% \db@col@id@end@ % \db@col@elt@w \begin {align*} \frac {df}{dx} & = \lim _{\Delta x \rightarrow 0}\frac {f(x + \Delta x) - f(x)}{\Delta x}\\ & = \lim _{\Delta x \rightarrow 0} \frac {\cos (x + \Delta x) - \cos (x)}{\Delta x}\\ & = \lim _{\Delta x \rightarrow 0} \frac {\cos x\cos \Delta x - \sin x\sin \Delta x - \cos x}{\Delta x}\\ & = \lim _{\Delta x \rightarrow 0} \frac {\cos x(\cos \Delta x - 1) - \sin x\sin \Delta x}{\Delta x}\\ & = \cos x\lim _{\Delta x \rightarrow 0}\frac {\cos \Delta x - 1}{\Delta x} - \sin x\lim _{\Delta x \rightarrow 0}\frac {\sin \Delta x}{\Delta x}\\ & = -1 \qquad \text {(using given results)} \end {align*}% \db@col@elt@end@ % \db@col@id@w 3% \db@col@id@end@ % % Column 4 \db@col@id@w 4% \db@col@id@end@ % \db@col@elt@w 3% \db@col@elt@end@ % \db@col@id@w 4% \db@col@id@end@ % % Column 5 \db@col@id@w 5% \db@col@id@end@ % \db@col@elt@w Theory% \db@col@elt@end@ % \db@col@id@w 5% \db@col@id@end@ % % End of row 15 \db@row@id@w 15% \db@row@id@end@ % \db@row@elt@end@ % }% \expandafter\global \expandafter\newcount\csname dtlrows@mth102\endcsname \expandafter\global \csname dtlrows@mth102\endcsname=15\relax \expandafter\global \expandafter\newcount\csname dtlcols@mth102\endcsname \expandafter\global \csname dtlcols@mth102\endcsname=5\relax \expandafter \gdef\csname dtl@ci@mth102@Label\endcsname{1}% \expandafter \gdef\csname dtl@ci@mth102@Question\endcsname{2}% \expandafter \gdef\csname dtl@ci@mth102@Answer\endcsname{3}% \expandafter \gdef\csname dtl@ci@mth102@Level\endcsname{4}% \expandafter \gdef\csname dtl@ci@mth102@Topic\endcsname{5}% \egroup \def\dtllastloadeddb{mth102}