Posted by Joel on August 12, 2002 at 17:13:27:
In Reply to: y=3^x posted by bana on August 12, 2002 at 07:53:27:
: Hi thre,
: I've been told that if y=3^x, then y'=(In3)3^x . how does it work with the rule In{g(x)}-> g'/g?
more generally, if y = a^x where a is any constant
then y' = (a^x)* ln(a)
also, it is true that if y = ln(u) where u is a function of x
then dy/dx = (1/u) * du/dx
so as you put it, if y = ln[g(x)]
then y' = [1/g(x)]*[g'(x)]
so, what's your question?