text: how do you differentiate 2^x? thanks!? i'm thinking its ln2 but not sure... y = 2^x  ln y = ln 2^x  d/dx ln y = d/dx ln 2^x  d/dx ln y = d/dx x*ln 2  pull the constant (ln 2) out:  y'/y = ln 2 * d/dx x  y'/y = ln 2  y' = y * ln 2  y' = 2^x * ln 2  *** remember this advice, kids.  whenever you want to get rid of a variable exponent during differentiation, use logarithmic differentiation.  using it will make things cleaner and easier.