SAN FRANCISCO (AP) — LinkedIn began the year with its largest quarterly loss since going public as the online professional networking service ramped up its investments in projects aimed at attracting more users on the lookout for better jobs and career advice.Despite the setback, the first-quarter results announced Thursday surpassed the analyst projections that sway investors. LinkedIn has cleared Wall Street’s financial hurdles in all 12 of its quarters as a public company, a stretch dating back to May 2011.Nevertheless, LinkedIn Corp. has fallen out of favor with investors amid concerns about the company’s rising expenses and slowing revenue growth. Management issued a forecast indicating those trends will extend into the current quarter ending in June.LinkedIn’s stock shed $7.02, or 4.4 percent, to $154.20 in Thursday’s extended trading.