\(K(x) = 5*x - \sqrt{x}=5*x - x^{\frac{1}{2}}\)
\(K´(x) = 5 - \frac{1}{2}*x^{\frac{1}{2}-1}=5 - \frac{1}{2}*x^{-\frac{1}{2}}\)
\(K´´(x) = (- \frac{1}{2})*(-\frac{1}{2})*x^{-\frac{3}{2}}= \frac{1}{4}*x^{-\frac{3}{2}}\)
\( \frac{1}{4}*x^{-\frac{3}{2}}=0\)
\( x^{-\frac{3}{2}}=0\) Hier gibt es keine Lösung.
Meinst du nicht: \(K´(x) = 0\) ?
\( 5 - \frac{1}{2}*x^{-\frac{1}{2}}=0\)
\( \frac{1}{2}*x^{-\frac{1}{2}}=5\)
\( 10=x^{-\frac{1}{2}} |*x^{\frac{1}{2}}\)
\( 10*x^{\frac{1}{2}}=1\)
\( x^{\frac{1}{2}}=\frac{1}{10} |^{2}\)
\( x=\frac{1}{100} \)