Is the posted solution to problem 2B-1, sub-problem b correct? It claims that the derivative of y=x^4-4x+1 is y'=x^3-4. It seems to me that the correct answer is 4x^3-4. Am I wrong, and if so why?

Question

Is the posted solution to problem 2B-1, sub-problem b correct?  It claims that the derivative of y=x^4-4x+1 is y'=x^3-4.  It seems to me that the correct answer is 4x^3-4.  Am I wrong, and if so why?

anonymous · Answer

Your answer is definitely correct. There must be an error in the solution.

anonymous · Answer

AH! I just posted that same question - looks like I'm not the only one who does the problem sets !! I wish there was a search function for already asked questions!!