Question 87509
{{{f(x) = x^2 - 3x + 4}}}


{{{f(x+h) = (x+h)^2 -3(x+h) +4}}}
{{{f(x+h) = x^2 +2xh+ h^2 -3x-3h +4}}}


{{{ (f(x+h) -f(x))/h= ((x^2+2xh+h^2 -3x-3h+4) -(x^2 -3x+4))/h }}}


Remove parentheses

{{{ (f(x+h) -f(x))/h= (x^2+2xh+h^2 -3x-3h+4 -x^2 +3x-4)/h }}}


Combine like terms:

{{{ (f(x+h) -f(x))/h= (2xh+h^2 -3h )/h }}}


Factor out the common factor of h:
{{{ (f(x+h) -f(x))/h= (h(2x+h -3) )/h }}}


Divide out the h factor:
{{{ (f(x+h) -f(x))/h= 2x+h -3 }}}


R^2 at SCC