Tesla Inc.'s profit plunged as rising costs undercut a record quarter of vehicle sales, exposing strains on its operations while Chief Executive Officer Elon Musk shifts focus away from the automotive business. Musk used Tesla's third-quarter earnings to talk up ambitious-but-opaque initiatives including the company's humanoid robot and artificial intelligence programs, and also pleaded with investors to back his trillion-dollar compensation package. But he offered few details about how Tesla will revive its core business selling electric vehicles after a 40% drop in operating profit. "We're left with this lingering uncertainty regarding what the near-term growth drivers will be," said Garrett Nelson, senior equity research analyst at CFRA.