Fix bug 2931
Fix bug 2932, and added randomization.
Remove extraneous PAR
Fix bug 2903
Added math objects
Added math objects
Fix bug 2861
Fix bug 2863
Fix bug 2865
Fix bug 2878
Remove textbook references
improve formatting, change error tolerance so that large values of r are more reliably handled.
Small fixes.
specify better limits for answer checking.
Fixing solution.
Merge branch 'master' of github.com:openwebwork/webwork-open-problem-library
Fix bug 2936
Fix bug 2912
Whitespace change
Fixing tag capitalization