First, multiple-choice questions (4 points for each small question, 40 points for * * *)
1, if it makes sense, then the range of letters is ()
:D:
2. The number of quadratic roots in the following formula is ()
⑴ ; ⑵ ; ⑶ ; ⑷ ; ⑸ ; ⑹
A: 2 B: 3 C: 4 D: 5.
3, known, then the value of ()
A:-1 b: 1 c: d:
4, the following calculation is correct ()
:D:
5, the following calculation is correct ()
:D:
6, the following quadratic formula, the same as the quadratic formula is ():
:D:
7. Simplify the quadratic root to get ()
A: B: C: D:30
8. If the root number of the simplest quadratic root is the same, the value of a is ().
A: B: C:a= 1 D:a= — 1
9, the value of the radical is equal to ()
A: -2 B: 2 C:2 D:4
10, the following quadratic formula, can be merged is ().
:D:
Fill in the blanks (4 points for each small question, 40 points for * * *)
1 1, calculation: _ _ _ _ _ _ _;
12, when _ _ _ _ _ _ _ _, the quadratic radical is meaningful in the real number range;
13, calculation: _ _ _ _ _ _ _ _ _;
14, calculation: _ _ _ _ _ _ _ _ _;
15, called a.
16. Contrast size: (fill in ">")
17, the quadratic root is meaningful if;
18, if true, then x satisfies _ _ _ _ _ _ _ _ _ _ _ _;
19. Observe and think about the following calculation process: ∫112 =1,∴ =1,∫/kl.
∴ = 1 1 1。 Guess: =;
20. Please note the following: ; ……
Then the fourth formula is in turn: the law you observe expressed by the equation should be