Question 43372
Given that {{{ f(x)=x^2+5 }}}


then {{{ f(a+h)=(a+h)^2+5 }}}
{{{ f(a+h)=a^2+2ah+h^2+5 }}}


and {{{ f(a)=a^2+5 }}}


hence f(a+h)-f(a) is {{{ (a^2+2ah+h^2+5) - (a^2+5) }}}
{{{ f(a+h)-f(a) = a^2+2ah+h^2+5 - a^2 - 5 }}}
{{{ f(a+h)-f(a) = 2ah+h^2+5 - 5 }}}
{{{ f(a+h)-f(a) = 2ah+h^2 }}}
{{{ f(a+h)-f(a) = h(2a+h) }}}


jon.