title: How to expand and compute log(a + b)?
body: <p>I would like to know the complete expansion of <code>log(a + b)</code>.</p>
  
  <p>For example</p>
  
  <pre><code>log(a * b) = log(a) + log(b);
  log(a / b) = log(a) - log(b);
  </code></pre>
  
  <p>Similar to this, is there any expansion for log(a + b)?</p>