# This is the correct Derivative?

1. Nov 4, 2012

### kLPantera

1. The problem statement, all variables and given/known data

Need to find the derivative:

y=logx/2-logx=logx*(2-log(x))^-1

3. The attempt at a solution

The derivative of log(x) is 1/xln(10) and the derivative of (2-log(x))^-1 is -(2-log(x))^-2*1/xln(10)?

This ended as

1/xln(10)(2-logx) - logx/xln(10)(2-log(x))^2

2-log(x)-log(x)/xln(10)(2-log(x))^2

Though the answer is 2/xln(10)(2-log(x))^2... so what am I doing wrong?

2. Nov 4, 2012

### Staff: Mentor

In general, more brackets and/or spaces would help. TeX syntax is even better: $\frac{\log(x)}{x}$.

I think you are missing ^(-1) in the first part and a minus sign in the second part. I don't see how the following line follows from that expression.
The answer is missing a minus, too?