Step 1 :The question is asking to rewrite the given expression as a single logarithm. To do this, we can use the properties of logarithms.
Step 2 :The properties of logarithms that we will use are: 1. \(a \log b = \log b^a\) 2. \(\log a - \log b = \log \frac{a}{b}\) 3. \(\log a + \log b = \log ab\)
Step 3 :Using these properties, we can rewrite the given expression as a single logarithm.
Step 4 :The expression \(4 \log x-2 \log \left(x^{2}+1\right)+2 \log (x-1)\) can be rewritten as a single logarithm as follows:
Step 5 :\(\boxed{\log \left(\frac{x^{4}(x-1)^{2}}{(x^{2}+1)^{2}}\right)}\)