题目若点P(a,b)P(a,b)P(a,b)在第二象限，∣a∣=5|a|=5∣a∣=5，b=4\sqrt {b}=4b=4，则点PPP的坐标为((( )))A.(−5,16)(-5,16)(−5,16)B.(5,16)(5,16)(5,16)C.(5,2)(5,2)(5,2)D.(−5,2)(-5,2)(−5,2)知识点：点的坐标的确定章节：未标注
