Question 140645
{{{f(x)=2-x^2}}}
{{{f(x+h)=2-(x+h)^2}}}
{{{f(x+h)=2-(x^2-2xh+h^2)}}}
{{{f(x+h)=2-x^2+2xh-h^2}}}
{{{f(x+h)-f(x)=2-x^2+2xh-h^2-(2-x^2)}}}
{{{f(x+h)-f(x)=2xh-h^2}}}
{{{(f(x+h)-f(x))/h=(2xh-h^2)/h}}}
{{{(f(x+h)-f(x))/h=2x-h}}}