// Numbas version: finer_feedback_settings {"name": "Logaritmer - forenkle uttrykk 3", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Logaritmer - forenkle uttrykk 3", "tags": [], "metadata": {"description": "

Simlify (expand) logarithmic expressions 

", "licence": "None specified"}, "statement": "

Forenkle uttrykket.

", "advice": "

Her bruker vi logaritmesetningene:

\n
    \n
  1. $\\ln(ab)=\\ln(a)+\\ln(b)$
  2. \n
  3. $\\ln\\left(\\dfrac{a}{b}\\right)=\\ln(a)-\\ln(b)$
  4. \n
  5. $\\ln\\left(a^{b}\\right)=b\\ln(a)$
  6. \n
\n

I tillegg bruker vi sammenhengen $\\ln(e)=1$.

\n

Vi skal forenkle uttrykket

\n

\\[\\ln\\left(\\var{b1}a^{\\var{c[0]}}\\right)-\\ln\\left(\\dfrac{b^{\\var{c[1]}}}{a^{\\var{c[2]}}}\\right)+\\ln\\left(\\dfrac{e^{\\var{c[3]}}}{\\var{b2}b^{\\var{c[4]}}}\\right)\\]

\n

Her kan det være en fordel å forenkle hvert ledd for seg først:

\n\n

Så setter vi sammen:

\n

$\\ln\\left(\\var{b1}a^{\\var{c[0]}}\\right)-\\ln\\left(\\dfrac{b^{\\var{c[1]}}}{a^{\\var{c[2]}}}\\right)+\\ln\\left(\\dfrac{e^{\\var{c[3]}}}{\\var{b2}b^{\\var{c[4]}}}\\right)\\\\
=\\var{ex[0]}\\ln(2)+\\var{c[0]}\\ln(a)-\\left(\\var{c[1]}\\ln(b)-\\var{c[2]}\\ln(a)\\right)+\\var{c[3]}-\\var{ex[1]}\\ln(2)-\\var{c[4]}\\ln(b)\\\\
=\\var{c[0]}\\ln(a)+\\var{c[2]}\\ln(a)-\\var{c[1]}\\ln(b)-\\var{c[4]}\\ln(b)+\\var{ex[0]}\\ln(2)-\\var{ex[1]}\\ln(2)+\\var{c[3]}\\\\
=\\underline{\\underline{\\var{ka}\\ln(a)-\\var{kb}\\ln(b)+\\var{k2}\\ln(2)+\\var{c[3]}}}$

\n

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$\\ln\\left(\\var{b1}a^{\\var{c[0]}}\\right)-\\ln\\left(\\dfrac{b^{\\var{c[1]}}}{a^{\\var{c[2]}}}\\right)+\\ln\\left(\\dfrac{e^{\\var{c[3]}}}{\\var{b2}b^{\\var{c[4]}}}\\right)$=[[0]]$\\ln(a)-$[[1]]$\\ln(b)+$[[2]]$\\ln(2)+$[[3]]

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