Find the error in the following incorrect application of L'Hopital's rule.

Therefore, the lim x--> 0 = .

I'm not sure what the problem is. My guess is that it has something to do with ignoring the 0 (that came from the derivative of 1) on the numerator of the 2nd derivative.

I know the value of 0 plugged in is correct. There didn't appear any faulty differentiation.

Another thought is that I should use a trig rule.

1 - cos (x) looks like it should be replaced by something.