I want check my answer in derivatives (part 2)

[r-soy]

I want check my answer in derivatives (part 2)

http://store1.up-00.com/Oct10/7uV34128.jpg

 

[Kevin_Axion]

Use Wolfram Alpha: http://www.wolframalpha.com/

 

[Mark44]

For 1, you multiplied correctly, but should simplify by combining the two x³ terms. When you differentiated, you have an error in the last term.
When you used the product rule, you differentiated incorrectly when you found u'. If u = 3 - x², u' = -2x, not -2x^-3 as you have. This is basically the same mistake that you made in the first part of this problem.

In 2, you only did this problem in one way - you didn't use the product rule. When you multiplied (x + 1/x) and (x - 1/x + 1) you have several mistakes. You ended up with two terms but there should be four.

 

[Mark44]

r-soy, have you figured these out? Many times you ask a question about your work, get a reply, and then don't say anything more until you have a new question.