Please slove the circled questions and explain step by step, especially 68.

1 Of History Explain in the time before electronic calculators and computers how logarithms turned compli- cated computations into easy arithmetic problems. Use the example V 4581. Extending the Ideas 68, Solve In x > VT. 69. Solve 1.2* = log1.2 x. 70.) Group Activity Work in groups of three. Have each group member graph and compare the domains for one pair of functions. (a) f(x) = 2 Inx + In (x - 3) and g(x) = Inx2(x - 3) (b) f(x) = In (x + 5) - In (x - 5) and g(x) = In - *+ 5 X - 5 (c) f(x) = log (x + 3)2 and 8(x) = 2 log (x + 3) Writing to Learn After discussing your findings, write a brief group report that includes your overall conclusions and insights. 71. Prove the change-of-base formula for logarithms. 72. Prove that f(x) = log x/In x is a constant function with re- stricted domain by finding the exact value of the constant log x/In x expressed as a common logarithm. Graph f(x) = In (In (x) ), and analyze it for domain, range, 73 continuity, increasing or decreasing behavior, symmetry, as- ymptotes, end behavior, and invertibility. In x 3 1x