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∵a,b均为单位向量,其中夹角为θ,∴p1:|a+b|>1⇔|a+b|2>1⇔1+1+2a•b>1⇔a•b>-12⇔cosθ>-12,而θ∈[0,π],∴θ∈[0,2π3),即p1正确,从而p2错误;p3:|a-b|>1⇔|a−b|2>1⇔1+1-2a•b>1⇔a•b<1...
∵a,b均为单位向量,其中夹角为θ,∴p1:|a+b|>1⇔|a+b|2>1⇔1+1+2a•b>1⇔a•b>-12⇔cosθ>-12,而θ∈[0,π],∴θ∈[0,2π3),即p1正确,从而p2错误;p3:|a-b|>1⇔|a−b|2>1⇔1+1-2a•b>1⇔a•b<1...