Question 1161566

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


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

{{{f(a+ h)=a^2+2ah+ h^2- 3a-3h+ 4}}}


{{{f(a)=a^2- 3a+ 4}}}



 {{{f(a+ h)- f(a)=a^2+2ah+ h^2- 3a-3h+ 4-(a^2- 3a+ 4)}}}

{{{f(a+ h)- f(a)=a^2+2ah+ h^2- 3a-3h+ 4-a^2+3a- 4}}}

{{{f(a+ h)- f(a)= h^2+2ah-3h}}}

{{{f(a+ h)- f(a)= h^2+(2a-3)h}}}