[ww-bugs] Bug 4102: New: A couple of errors in hard-coded answers in problem "Library/UCSB/Stewart5_3_5/Stewart5_3_5_58/Stewart5_3_5_58.pg"

[bugzilla-daemon at webwork.maa.org]

http://bugs.webwork.maa.org/show_bug.cgi?id=4102

           Summary: A couple of errors in hard-coded answers in problem
                    "Library/UCSB/Stewart5_3_5/Stewart5_3_5_58/Stewart5_3_
                    5_58.pg"
           Product: Problem Libraries
           Version: unspecified
          Platform: PC
               URL: http://www.skidmore.edu/~mhuibreg
        OS/Version: Windows
            Status: NEW
          Severity: trivial
          Priority: P5
         Component: Library (OPL)
        AssignedTo: gjennings at csudh.edu
        ReportedBy: mhuibreg at skidmore.edu
                CC: mhuibreg at skidmore.edu
        Web browser Firefox
           version:
    Browser version 59.0.1
            number:


This problem presents the graph of a function f and then asks for the
derivatives of four functions obtained as compositions involving f to be
estimated from the graph.  The answers to parts a) and c) of the problem (which
are hard-coded in the .pg file) appear to have the wrong sign.  In part a) the
students are to find the derivative of f(f(x)) at x = 2.  The chain rule gives
f'(f(x))f'(x).  From the graph, we see that (approximately) f(2) = 1, f'(1) =
-1, and f'(2) = -1/2.  The answer should therefore be (-1)(-1/2) = 1/2
(approximately), but the answer is typed in as -1/2.  Part c) depends on part
a), and is likewise off by a minus sign.  Parts b) and d) are OK.

-- 
Configure bugmail: http://bugs.webwork.maa.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are watching all bug changes.