Yahoo posted net income of $542.2 million, or 37 cents a share, for the first quarter of 2008, more than tripling earnings. Revenue rose 9%. Those results exceeded analysts’ forecasts, and come as the company fends off a takeover attempt by Microsoft, the Los Angeles Times reports. Microsoft contends the results don’t affect the value of Yahoo and that its cash-and-stock offer, as well as a Saturday deadline for Yahoo to accept or decline the deal, remain unchanged.