China's Xiaomi Corp posted a 43% slump in first-quarter net profit on Tuesday, as its smartphone business was pressured by high memory chip costs.The Chinese smartphone and electric-vehicle maker reported 6.1 billion yuan ($899 million) adjusted net profit for the January-March period.That compared with the average analyst estimate of 6.4 billion yuan, according to LSEG data.Xiaomi is investing heavily ?in electric ?vehicles and artificial ?intelligence, seeking new revenue drivers beyond its core handset business.Its EV business is growing but still dragging ?on earnings because of heavy investment and lower margins.The company reported 19 billion yuan in revenue ?for its EV…