Logarithms

[Penguins]

I don't know how to start solving this question:

A curve, C, has equation y = x - 2 - 2 log x, where x > 0.
The vertical lines x = 6 and x = 7 meet the curve at points R and S respectively.
Show that the y-coordinate of R is 4 - log 36

(all the logs are to base 10)

Any help would be much appreciated!!

[MathsMan]

When x=6
y=6-2-2log6 ............... Use the power rule for logs
=4-log6
=4-log 36

[Penguins]

*slaps forehead*
It's so blindingly obvious! Thank you!!