7.Let [img=199x61]1802dde9690822d.png[/img] .Does [img=62x33]1802dde9710faf4.png[/img]exists ?
A: (A) Yes, since [img=196x27]1802dde97ac0dbf.png[/img] for any [img=46x20]1802dde9831551a.png[/img], by pinching theorem, [img=62x33]1802dde98b6a13d.png[/img] exists.
B: (B) Yes, since [img=180x27]1802dde995267d8.png[/img] for any [img=46x20]1802dde9831551a.png[/img], by pinching theorem, [img=62x33]1802dde98b6a13d.png[/img] exists.
C: (C) No, since there exists some [img=46x20]1802dde9831551a.png[/img] such that [img=196x27]1802dde9b73b240.png[/img] and some [img=46x20]1802dde9831551a.png[/img] such that [img=196x27]1802dde97ac0dbf.png[/img], we can't apply pinching theorem.
D: (D) None of above explanation is correct.
A: (A) Yes, since [img=196x27]1802dde97ac0dbf.png[/img] for any [img=46x20]1802dde9831551a.png[/img], by pinching theorem, [img=62x33]1802dde98b6a13d.png[/img] exists.
B: (B) Yes, since [img=180x27]1802dde995267d8.png[/img] for any [img=46x20]1802dde9831551a.png[/img], by pinching theorem, [img=62x33]1802dde98b6a13d.png[/img] exists.
C: (C) No, since there exists some [img=46x20]1802dde9831551a.png[/img] such that [img=196x27]1802dde9b73b240.png[/img] and some [img=46x20]1802dde9831551a.png[/img] such that [img=196x27]1802dde97ac0dbf.png[/img], we can't apply pinching theorem.
D: (D) None of above explanation is correct.
举一反三
- 3. Let [img=161x53]1802dde8d59661c.png[/img] and [img=180x61]1802dde8df7d956.png[/img].Determine whether [img=62x33]1802dde8e7e5fb9.png[/img] and [img=61x33]1802dde8f088425.png[/img] exist or not. A: (A) [img=62x33]1802dde8f81f6da.png[/img] and [img=61x33]1802dde8ff2f966.png[/img] both exist. B: (B) [img=62x33]1802dde8f81f6da.png[/img] exists but [img=61x33]1802dde8ff2f966.png[/img] does not exist. C: (C) [img=62x33]1802dde8f81f6da.png[/img] does not exist but [img=61x33]1802dde8ff2f966.png[/img] exists. D: (D) [img=62x33]1802dde8f81f6da.png[/img] and [img=61x33]1802dde8ff2f966.png[/img] do not exist.
- 下列的推理结构中哪个是正确的推理形式()。 未知类型：{'options': ['([img=8x14]17e4385a99bb660.jpg[/img] x)P(x) ∧ ([img=8x14]17e4385a99bb660.jpg[/img]x)Q(x) → ([img=8x14]17e4385a99bb660.jpg[/img]x)(P(x) ∧Q(x))', ' ([img=8x14]17e4385a99bb660.jpg[/img] x)P(x) → ([img=8x14]17e4385a99bb660.jpg[/img]x)(P(x) ∧ Q(x))', ' ([img=8x14]17e4385a99bb660.jpg[/img]x)(P(x) ∨ Q(x)) → ([img=8x14]17e4385a99bb660.jpg[/img]x)P(x) ∨([img=8x14]17e4385a99bb660.jpg[/img]x)Q(x)', ' ([img=8x14]17e4385a99bb660.jpg[/img]x)(P(x)∨ Q(x)) → ([img=8x14]17e4385a99bb660.jpg[/img] x)P(x) ∧ ([img=8x14]17e4385a99bb660.jpg[/img] x)Q(x)'], 'type': 102}
- 下列的推理结构中哪个是正确的推理形式()。 未知类型：{'options': ['([img=8x14]17e4385aa223929.jpg[/img]x)(P(x) ∨Q(x)) → ([img=8x14]17e4385aa223929.jpg[/img]x)P(x) ∧ ([img=8x14]17e4385aa223929.jpg[/img]x)Q(x)', ' ([img=8x14]17e4385aa223929.jpg[/img]x)(P(x) ∨ Q(x)) → ([img=8x14]17e4385aa223929.jpg[/img]x)P(x) ∨ ([img=8x14]17e4385aa223929.jpg[/img]x)Q(x)', ' ([img=8x14]17e4385aa223929.jpg[/img]x)P(x) → ([img=8x14]17e4385aa223929.jpg[/img]x)(P(x) ∧Q(x))', ' ([img=8x14]17e4385aa223929.jpg[/img]x)P(x) ∧([img=8x14]17e4385aa223929.jpg[/img]x)Q(x) → ([img=8x14]17e4385aa223929.jpg[/img]x)(P(x) ∧ Q(x))'], 'type': 102}
- 下列4个集合中是空集的是（） A: ｛x|[img=18x22]1802f060e2f728f.png[/img]+1=0｝ B: ｛x|[img=18x22]1802f060e2f728f.png[/img]<-x｝ C: ｛x|[img=18x22]1802f060e2f728f.png[/img]=0｝ D: ｛x|[img=18x22]1802f060e2f728f.png[/img]-1=0｝
- 下列4个集合中是空集的是（） A: ｛x|[img=18x22]1803d021d498831.png[/img]+1=0｝ B: ｛x|[img=18x22]1803d021d498831.png[/img]<-x｝ C: ｛x|[img=18x22]1803d021d498831.png[/img]=0｝ D: ｛x|[img=18x22]1803d021d498831.png[/img]-1=0｝