Natural log differentiation question

[SYoungblood]

Homework Statement

f(x) = 1/ln (10-x) -- I would assume it to be a fairly simple equation, but I am screwing it up

Homework Equations

What is f'(x)?

The Attempt at a Solution

f'(x) = (ln (10-x))^-1
= -(ln (10-x))^-2 * -1 * 1/(10-x) -- 2 negatives cancel out
= 1/(10-x) (ln(10-x))2 -- This is as far as I got and I just can tell it isn't correct.

Thank you in advance for all help.

 

[LCKurtz]

Homework Statement

f(x) = 1/ln (10-x) -- I would assume it to be a fairly simple equation, but I am screwing it up

Homework Equations

What is f'(x)?

The Attempt at a Solution

f'(x) = (ln (10-x))^-1
= -(ln (10-x))^-2 * -1 * 1/(10-x) -- 2 negatives cancel out
= 1/((10-x) (ln(10-x))^2) -- This is as far as I got and I just can tell it isn't correct.

Thank you in advance for all help.

Except for the above missing parentheses and exponentiation symbol, it is correct.

 

[SYoungblood]

Thank you