网址:http://m.1010jiajiao.com/timu_id_15929[举报]
已知函数y=f(x)在点(2,1)处的切线与直线3x-y-2=0平行,则y′|x=2等于
A.-3 B.-1 C.3 D.1
A.-3 B.-1 C.3 D.1