5+mi_(5+mi)(0-3m15+2m2.D由题意得,z=2-3i(2-3i)(2+3)3,10-m=015+2m≠0解得m=一,故选D.
3.C该组数据的极差为36,众数为34,中位数为29.5,平均数为30+×(-13-7-5-4-3+2+44+19+23)=32,观察选项可知,故选C4.A若f(x)=2x2-mx+hx在(O,+∞)上单调递增,则f(x)=4x-m+-≥0,即4x+-≥m,则m≤4,故选A.2 tan a
5.A由题意得,tana=2,∴tan2a1-tan"a1-tan7.故选A1+ tan 2ar