18: This is a plain logarithm, so the logarithmic expansion seems an obvious start. However, creating terms (x − 2) is less obvious. Traditionally we start by writing

ln((x − 2) + 2),

but logarithm does not allow us to get rid of the "+2" part algebraically, which is a problem.

On the other hand, there is a chance to change this expression into the form ln(1 + y) and then apply appropriate expansion. Try it.

An interesting alternative is to express ln(x) as an integral of 1/x, which can be expanded using the geometric expansion with center 2.

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