Question

Find f(a), f(a + h), and the difference quotient
(f(a + h) − f(a))/h
where h ≠ 0.
f(x) = 7 − 4x + 3x2

Answer 1

\[f(a+h) = 7-4(a+h)+3(a+h)^{2}\]
\[f(a+h) - f(a) = 7-4(a+h)+3(a+h)^{2} - (7-4a+3a ^{2})\]
=
\[6ah + 3h ^{2} - 4h\]

After dividing out by h, you should get
6a - 4 + 3h