Khan/khan-exercises — Issue #14247: Chain rule 1 - Small Mistake in Answer
Author: KhanBugz
Created: 2012-02-20 20:40:34+00:00
State: open
Labels: chrome, wrong-or-unclear

Reporter: manndarryl@gmail.com

I'm just learning derivatives & chain rule; however, from what I understand the derivative of -2 would be 0.

Here is the problem/answer in question.

Question:
g(x) = −5x^4−2x^3−x^2−2x−2−6x^−1)^3

This was said to be the correct answer:
g'(x) = (3(−5x^4−2x^3−x^2−2x−2−6x^−1)^2)(−20x^3−6x^2−2x−2+6x^−2)

Notice the -2 near the end before +6x^-2. I believe this should not be there.

Thanks for hearing this issue. If I am incorrect in this, sorry for taking up your time.

[chain_rule_1.html?seed=197&problem=0](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/chain_rule_1.html?seed=197&problem=0&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/chain_rule_1.html?seed=197&problem=0&debug&activity=%5B%5B%22correct-activity%22%2C%22%5C%22None%20of%20the%20above.%5C%22%22%2C27%5D%5D)

["None of the above."]

Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.46 Safari/535.11

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