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Deriver uttrykkene.
", "advice": "a)
\nHer er det lurt å forenkle uttrykket før vi deriverer. Vi bruker logaritmesetningene:
\n$y=\\simplify{ln(x^{a})+{b}ln({c}x)}=\\simplify{{a}ln(x)}+\\simplify{{b}(ln({c})+ln(x))}=\\simplify{({a}+{b})ln(x)+{b}ln({c})}$.
\nVi kan da derivere leddvis, og får
\n\\[ y'=(\\simplify{({a}+{b})ln(x)})'+(\\var{b}ln(\\var{c}))'=\\simplify{({a}+{b})/x}+0=\\underline{\\underline{\\simplify{({a}+{b})/x}}}\\]
\n\nb)
\nHer bør vi også forenkle først:
\n$y=\\simplify{ln(x^{a}/(sqrt(x)))}=\\ln(x^{\\var{a}}-\\simplify{ln(sqrt(x))}=\\var{a}\\ln(x)-\\ln(x^{\\frac{1}{2}})=\\var{a}\\ln(x)-\\frac{1}{2}\\ln(x)=\\simplify{((2*{a}-1)/2)}\\ln(x)$.
\nDa får vi:
\n\\[y'=(\\simplify{((2*{a}-1)/2)}\\ln(x))'=\\underline{\\underline{\\simplify{((2*{a}-1)/(2x))}}}\\]
\n\nc)
\nDet finnes ingen regler for å forenkle logaritmen når argumentet er en sum.
\nHer lønner det seg å huske \"snarveien\" $\\left(\\ln(u)\\right)=\\dfrac{u'}{u}$. Vi trenger da bare å velge $u$ og regne ut $u'$:
\n$u=\\simplify[unitFactor,!collectNumbers]{x^{d}+{e}x}, \\qquad u'=\\simplify{{d}x^{{d}-1}+{e}}$
\nVi får da at $y'=\\dfrac{u'}{u}=\\underline{\\underline{\\dfrac{\\simplify{{d}x^{{d}-1}+{e}}}{\\simplify{x^{d}+{e}x}}}}$.
\n\nEllers må vi bruke kjerneregelen fullt ut:
\n$u=\\simplify[unitFactor,!collectNumbers]{x^{d}+{e}x}, \\qquad u'=\\simplify{{d}x^{{d}-1}+{e}}$
\n$y(u)=\\ln(u), \\qquad y'(u)=\\dfrac{1}{u}$
\n$y'=y'(u)\\cdot u' = \\dfrac{1}{u}\\cdot\\simplify{{d}x^{{d}-1}+{e}}=\\dfrac{\\simplify{{d}x^{{d}-1}+{e}}}{\\simplify{x^{d}+{e}x}}$
\n\nd)
\nHer må vi bruke kjerneregelen:
\n$u=\\simplify{x^{d}+x^{f}}, \\qquad u'=\\simplify{{d}x^{{d}-1}+{f}x^{{f}-1}}$
\n$y(u)=e^{u}, \\qquad y'(u)=e^{u}$
\n$y'=y'(u)\\cdot u'=e^{u}\\cdot (\\simplify{{d}x^{{d}-1}+{f}x^{{f}-1}})=\\underline{\\underline{(\\simplify{{d}x^{{d}-1}+{f}x^{{f}-1}})e^{\\simplify{x^{d}+x^{f}}}}}$
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\n$y'=$[[0]]
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\n$y=$ [[0]]
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