Question

Find the derivative.

Answer 1

\[\frac{ 1 }{\left( x+1 \right)^{2} } \]

Answer 2

You may want to write the expression as (x+1)^-2 and now use the power rule.

Answer 3

Oh okay thanks. I'll need chain rule too, right? Or is that not needed for this problem?

Answer 4

Yes.

Answer 5

But here, the derivative of (x + 1) is 1. so chain rule doesnt change anything.

Answer 6

the answer that my textbook gives is \[\frac{ -2 }{\left( x+1 \right) ^{3} }\].
how do I get to that answer?

Answer 7

that's what I can't figure out

Answer 8

exactly..thats what you get....using the pwer rule, you get

-2(x + 1) ^ (-3) which is identical to your book's answer.

Answer 9

Keep in mind, that (x+1) ^ (-3) = 1/(x+1)^3

Answer 10

Oh. I see what I was doing wrong. When I used the power rule, I subtracted the exponent wrong so I wasn't getting a -3. Thank you :)