Posted by Megan on .
f(x)=x(squared)+x3. compute the difference quotient: (f(x+h)f(x))/h

elementary functions 
Reiny,
f(x+h) = (x+h)^2 + x+h  3
= x^2 + 2xh + h^2 + x + h  3
then ( f(x+h)  f(x) )/h
= (x^2 + 2xh + h^2 + x +h  3  x^2  x + 3)/h
= ( 2xh + h^2 +h)/h
= h(2x + h + 1)/h
= 2x + h + 1 , h ≠0