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A 1-cos x B 1+cos x C 2-cos x D 2+cos x

A <img src="https://www.beizhujiaoyu.com/uploads/202208/156075203639191.png" alt="" /> B <img src="https://www.beizhujiaoyu.com/uploads/202208/156075204485111.png" alt="" /> C <img src="https://www.beizhujiaoyu.com/uploads/202208/156075205299441.png" alt="" /> D <img src="https://www.beizhujiaoyu.com/uploads/202208/156075205838661.png" alt="" />

A <img src="https://www.beizhujiaoyu.com/uploads/202208/156075209922831.png" alt="" /> B <img src="https://www.beizhujiaoyu.com/uploads/202208/156075210736281.png" alt="" /> C <img src="https://www.beizhujiaoyu.com/uploads/202208/156075211312341.png" alt="" /> D <img src="https://www.beizhujiaoyu.com/uploads/202208/156075212031551.png" alt="" />

A 0 B 1 C 2 D 3

A <img src="https://www.beizhujiaoyu.com/uploads/202208/15607521534461.png" alt="" /> B <img src="https://www.beizhujiaoyu.com/uploads/202208/156075216087741.png" alt="" /> C <img src="https://www.beizhujiaoyu.com/uploads/202208/156075216864921.png" alt="" /> D <img src="https://www.beizhujiaoyu.com/uploads/202208/156075217436751.png" alt="" />

A <img src="https://www.beizhujiaoyu.com/uploads/202208/156075220436721.png" alt="" /> B <img src="https://www.beizhujiaoyu.com/uploads/202208/156075221247341.png" alt="" /> C <img src="https://www.beizhujiaoyu.com/uploads/202208/156075222026131.png" alt="" /> D <img src="https://www.beizhujiaoyu.com/uploads/202208/156075222613491.png" alt="" />

A 1/2 B 1 C 2 D 3

A 6y B 6xy C 3x D 3x²

A 0 B 1 C 2 D +∞