"from d to k" changed to "from d to j" (there is no option k).
Removed extraneous word "not"
Fixed typo (x --> n)
Fixed typo (sign error)
Fixed typo in solution
Fix tags
Fix bug 3170
Protecting "pi" as bareword
Change y= to x^2= in problem text

Used Simmons & Krantz section 1.2 problem 1j for the correct statement of the problem.
Fix bug 3150
Merge branch 'master' of github.com:openwebwork/webwork-open-problem-library
Fixed perl error "uninitalized value $ans2"
The function needs to be continuously differentiable.
Added line breaks before part A, use built-in $PI, and minor whitespace changes in the source
Added $BR to clarify roles of input blanks; added units.
Switched to standard helpLink for interval notation.
Merge remote-tracking branch 'upstream/master'