Fix numerous TeX errors

Indiana/Indiana_setSeries8Power/eva8_5a.pg  Fixed TeX errors (unescaped '#' in TeX mode)
Indiana/Indiana_setSeries8Power/eva8_5a_2.pg  same
Indiana/Indiana_setSeries8Power/eva8_5c.pg  same
Indiana/Indiana_setSeries8Power/eva8_6f.pg  same
Indiana/Indiana_setSeries8Power/eva8_6g.pg  same
Indiana/Indiana_setSeries9Taylor/e8_7_5.pg  same
Indiana/Indiana_setSeries8Power/eva8_5b.pg  Fixed TeX errors (unescaped '#' in TeX mode, and missing \right| )
Indiana/Indiana_setSeries8Power/eva8_6d.pg  Fixed PG error ($ $ --> \( \) ); clarified first answer blank.
Indiana/Indiana_setSeries8Power/eva8_6h.pg  Fixed TeX errors (misplaced alignment tabs '&')
Rochester/setDiffEQ11ModelingWith2ndOrder/ur_de_11_2.pg  Cleaned up TeX errors and typos in hint.
Rochester/setDiffEQ11ModelingWith2ndOrder/ur_de_11_3.pg  (same)
Rochester/setDiffEQ11ModelingWith2ndOrder/ur_de_11_4.pg  (same)
ma122DB/set10/s4_10_43.pg  Fixed TeX errors in alignment.
Indiana/Indiana_setIntegrals5Trig/ur_in_5_3.pg  Fixed TeX error (missing \right )
Indiana/Indiana_setSeries5IntegralTest/eva8_3_1.pg  Fixed TeX errors and rewrote solution.