Old computer programs used to only allow exponential functions with a certain base. If you needed an exponential in a different base, it had to be converted first. At right is the procedure for rewriting a base 2 exponential function with a base of 10. Use this technique to rewrite y = 3x as an exponential function with a base of 10.
y = 2x
log y = x log 2
y = 10x log 2
Notice the second step of the model problem above. It is the Power Law of Logarithms; this law will become more and more necessary as this course progresses.