Find f(a), f(a + h),

and the difference quotient
f(a + h) − f(a)
------------------
h
,
where h ≠ 0.

f(x) = 4 − 6x + 7x2

f(a)=
f(a + h) =
f(a + h) − f(a)
----------------- =
h

1 answer

f(x) = 4 − 6x + 7x2

7(x + h)^2 -6(x+h) +4-(7x^2 -6x +4))/h

7( x^2 xh+ xh + h^2) -6x -6h + 4 -7x^2 +6x -4))/h
(7x^2 +14xh + 7h^2 -6x -6h +4 -7x^2 + 6x -4)/h
(14xh + 7h^2 -6h)/h
h(14x +7h -6)/h
14x + 7h -6
lim(h->0) 14x + 7h -6 = 14x -6