ابتدا ضابطۀ توابع $g,f$ را می‌یابیم:

$f:\left( 4,0 \right),\left( 0,4 \right)\Rightarrow $ شیب $m=\frac{4-0}{0-4}=-1\Rightarrow y=-x+b\xrightarrow{\left( 0,4 \right)}b=4\Rightarrow f\left( x \right)=-x+4$

$g:\left( 0,0 \right),\left( 5,3 \right)\Rightarrow $ شیب ${m}'=\frac{3-0}{5-0}=\frac{3}{5}\Rightarrow y=\frac{3}{5}x+b\xrightarrow{\left( 0,0 \right)}b=0\Rightarrow g\left( x \right)=\frac{3}{5}x$

$h\left( x \right)=\frac{g\left( x \right)}{f\left( x \right)}=\frac{\frac{3}{5}x}{-x+4}=\frac{3x}{-5x+20}\Rightarrow {h}'\left( x \right)=\frac{3\left( -5x+20 \right)-\left( -5 \right)\times 3x}{{{\left( -5x+20 \right)}^{2}}}=60{{\left( -5x+20 \right)}^{-2}}$ 

${h}''\left( x \right)=60\left( -2 \right)\left( -5 \right){{\left( -5x+20 \right)}^{-3}}=\frac{600}{{{\left( -5x+20 \right)}^{3}}}\Rightarrow {h}''\left( 2 \right)=\frac{600}{1000}=\frac{6}{10}=0/6$