Question 1: What does a complete set of U mean in mathematics * * *? * * * The complete set in the topic means that all the elements of this topic are only considered in the set U, and there can be no elements beyond the scope of the complete set.

For example, if the integer n is a complete set, then this topic cannot have decimals and fractions.

If the natural number * * * is set as a complete set, then negative integers cannot appear.

In most cases where the complete set is not directly specified, the default real number *** R is generally used as the complete set.

Question 2: What does the Complete Works of Mathematics in Senior One mean? Generally speaking, if a * * * contains all the elements involved in the problem we are studying, then this * * * is called the complete works, usually denoted as U.

AUB=S

The second question 10-a should belong to P, right? * * * and * * * are inclusive relations, and elements and * * * are subordinate relations.

The answer should be 3 1.

Question 3: In mathematics, what is the letter * * * and what does it mean? The more detailed, the better! Thank you n: non-negative integer * * or natural number * * {0, 1, 2,3, ...}

N* or N+: positive integer * * {1, 2,3, ...}

Z: integer * * {...,-1,0,1,...}

P: prime number * * *

Q: Rational number * * *

Q+: Positive Rational Number * * *

Q-: negative rational number * * *

R: real number * * *

R+: positive real number * * *

R-: negative real number * * *

C: complex number * * *

? : empty * * * (* * nothing is called empty * * *)

U: all * * * (including all the elements discussed in a question * * *)

Question 4: What do you mean by complete works? Can all * * * really be called complete works? 10. The complete works include all TV plays. * * * in one place, so the two concepts are different.

Question 5: What does I=R mean in mathematics * * *? I represent a complete set, R is a real number set, I=R, and the complete set is a real number set.

For example, I = R, AUB = I.

A=, find B.

AUB=I=R

AUB=R

B=CuA, because AUB=I, so B=CuA.

A=, CuA=(- infinity, 1)U(2,+infinity)

B=CuA=(- infinity, 1)u(2,+infinity)

Question 6: Ask a math problem in Grade Two. Both your idea and the teacher's idea are right.

Such an idea

C is known to belong to all real numbers.

The equation c +(a-2)c+a+ 1 -2a= 0 has a solution.

So △≥0, so we get a ∈ [0 0,4/3].

Yes, you already know that C is on [0,4/3].

But when c belongs to all real numbers, A ∈ [0 0,4/3] has been proved.

And c ∈ [0 0,4/3] is just a special case where c belongs to all real numbers.

So we must prove the result of A ∈ [0 0,4/3].

Maybe you want to say that C is in [0,4/3].

You can find a smaller range of a.

The title requirement is to verify a, b, c ∈ [0 0,4/3]

There is no need to seek a smaller scope.

In fact, C ∈ [0 0,4/3] does not narrow the scope of A.

The proof is complicated, so I won't list it.

So both you and the teacher are right.

Just use c to find the range of a on [0,4/3].

The result is also a, b, c ∈ [0 0,4/3].