Linearization of ln(7x) at a=1/7

[h0meless]

Homework Statement

find the linearization of L(x) at a.
f(x)=ln7x, a=1/7

Homework Equations

f(a)+f'(a)(x-a)

The Attempt at a Solution

i got f(1/7)=0 and f'(1/7)=9.12
then shouldn't it be 0+.9.12(x-0)=9.12x?

 

[TheoMcCloskey]

Not quite - Check your derivative again - if it helps, remember, ln(ax) = ln(a) + ln(x).