Tech mogul and CEO of Tesla and SpaceX Elon Musk was seen cheering on Donald Trump as the latter was sworn in as president on Monday.

Mr. Musk Goes to Washington: Elon Musk's ubiquitous presence at Trump's inauguration See photos of Elon Musk at the inauguration below.

As President Donald Trump was sworn into office Monday, among those present at the intimate inauguration ceremony inside the Rotunda of the Capitol was tech mogul Elon Musk. During the event ...