Question

College Algebra: reviewing for Final Exam!
If f(x)=x^2+2x, then find f(a+h)-f(a).
What's the first thing I do?

Answer 1

find f(a+h) by replacing your `x` with `a+h`

Answer 2

next find f(a) by replacing `x` with `a`

Answer 3

So, it would look like this:
\[f(a-h)=(a-h)^{2}+2(a-h)\]

Answer 4

and \[f(a)=a^{2}+2a\]

Answer 5

it's not `f(a-h)` it's `f(a + h)`

Answer 6

oops lolx

Answer 7

\[f(a+h)=a ^{2}+h ^{2}+2a+2h\]

Answer 8

Would I add f(a)=a^2+2a to that equation?

Answer 9

f( a + h) = (a+h)^2 +2(a+h) = \(a^2 +2ah+h^2 + 2a +2h\)

Answer 10

Do you see your mistake?

Answer 11

So you did this: