Using derivative to prove inequality: 0
Let f (x) = tanx-x-x ^ 3 / 3
f'(x)=secx^2-1-x^2=(tanx)^2-x^2
When 00
So f '(x) > 0
So f (x) is at 0 x + (x ^ 3) / 3
What is the derivative of 1 / (LNX)?
Divide by derivative
What is the derivative of (1 / LNX) '
-1/[x(lnx)^2]