9im的知识精选

若复数z=(m+2)+(m2-9)i(m∈R)是正实数,则实数m的值为(  )A.-2            ...
问题详情:若复数z=(m+2)+(m2-9)i(m∈R)是正实数,则实数m的值为()A.-2                           B.3C.-3                           D.±3【回答】B[由题知解得m=3.故选B...
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