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已知||=3,||=4,(+)×(+3)=33,则与的夹角为( )
A.30° B.60° C.120° D.150°
已知||=3,||=4,(+)×(+3)=33,则与的夹角为 ( )
已知||=3,||=4,(+)×(+3)=33,则与的夹角为