Question 950294
{{{f(x)=(1/9)x}}}
{{{f(x+h)=(1/9)(x+h)=(1/9)x+(1/9)h}}}
{{{f(x+h)-f(x)=(1/9)x+(1/9)h-(1/9)x=(1/9)h}}}
{{{(f(x+h)-f(x))/h=(1/9)(h/h)=highlight(1/9)}}}