What is the derivative of ln(2x)?

2 Answers
Apr 3, 2016

(ln(2x))' = 1/(2x) * 2 = 1/x.

Explanation:

You use the chain rule :

(f @ g)'(x) = (f(g(x)))' = f'(g(x)) * g'(x).

In your case : (f @ g)(x) = ln(2x), f(x) = ln(x) and g(x) = 2x.

Since f'(x) = 1/x and g'(x) = 2, we have :

(f @ g)'(x) = (ln(2x))' = 1/(2x) * 2 = 1/x.

Apr 3, 2016

1/x

Explanation:

You can also think of it as

ln(2x) = ln(x) + ln(2)

ln(2) is just a constant so has a derivative of 0.

d/dx ln(x) = 1/x

Which gives you the final answer.