Skillnad mellan versioner av "2.3a Lösning 10"

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(8 mellanliggande versioner av samma användare visas inte)
Rad 1: Rad 1:
:<math> f(x+h) - f(x) = {1 \over x+h} - {1 \over x} = {x \over x\,(x+h)} - {x+h \over x\,(x+h)} = {x - (x+h) \over x\,(x+h)} = {x - x - h \over x\,(x+h)} = {- h \over x\,(x+h)} </math>
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:<math> \begin{array}{rcl} f(x+h) - f(x) & = & {1 \over x+h} - {1 \over x} = {x \over x\,(x+h)} - {x+h \over x\,(x+h)} = {x - (x+h) \over x\,(x+h)} = {x - x - h \over x\,(x+h)} = \\
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                  \\
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                                        & = & {- h \over x\,(x+h)}
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\end{array}</math>
  
  
:<math> f\,'(x) = \lim_{h \to 0} {f(x+h) - f(x) \over h} = \lim_{h \to 0} {{- h \over x\,(x+h)} \over h} = \lim_{h \to 0} {{- h \over x\,(x+h)} \over {h \over 1}} = \lim_{h \to 0} \; {- h\cdot 1 \over h\cdot x\,(x+h)} </math>
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:<math> {f(x+h) - f(x) \over h} = {- h/h \over x\,(x+h)}= {- 1 \over x\,(x+h)} </math>
  
  
::<math> = \lim_{h \to 0} \; {- 1 \over x\,(x+h)} = \lim_{h \to 0} \; {- 1 \over x^2 + x\,h} = - \, {1 \over x^2} </math>
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:<math> \lim_{h \to 0} {f(x+h) - f(x) \over h} = \lim_{h \to 0} \; {- 1 \over x\,(x+h)} = {- 1 \over x\,(x+0)} = - \, {1 \over x^2} </math>

Nuvarande version från 28 september 2014 kl. 20.59

\[ \begin{array}{rcl} f(x+h) - f(x) & = & {1 \over x+h} - {1 \over x} = {x \over x\,(x+h)} - {x+h \over x\,(x+h)} = {x - (x+h) \over x\,(x+h)} = {x - x - h \over x\,(x+h)} = \\ \\ & = & {- h \over x\,(x+h)} \end{array}\]


\[ {f(x+h) - f(x) \over h} = {- h/h \over x\,(x+h)}= {- 1 \over x\,(x+h)} \]


\[ \lim_{h \to 0} {f(x+h) - f(x) \over h} = \lim_{h \to 0} \; {- 1 \over x\,(x+h)} = {- 1 \over x\,(x+0)} = - \, {1 \over x^2} \]