Is a number of countable nouns plural or singular

Is a number of countable nouns plural or singular

A number of students
A number of means many
How many
When the Yong, the old are subjects, do they use the singular or the plural
The person in front of you, please inquire before answering!
The old, the young refers to a group of people, equal to the old people, the young people
So the predicate must be plural
Usually singular, because they refer to a group, is a class
singular
Is number of students a plural verb
A number of students
The number of the students is singular
complex
The number of + noun singular
Only one of, the only one of, is the subject, and the predicate is singular or plural, especially only one of
Only one of + plural
The only one of + singular
The first is plural and the second is singular
It's all singular!
The predicate verb is singular because one is the subject
Given the function f (x) = e ^ (x-m) - ln (2x), when m ＜ = 2, it is proved that f (x) > - LN2
F (x) = e ^ (x-m) - ln (2x) > = e ^ (X-2) - ln (2x), that is to say, e ^ (X-2) - ln (2x) > - LN2, that is, e ^ (X-2) > ln (2x) - LN2 = 1nx, let g (x) = e ^ (X-2) - 1nx, G '(x) = e ^ (X-2) - 1 / x, obviously G' (x) increases. Let the root of G '(x) = e ^ (X-2) - 1 / x = 0 be x1, then G (x) decreases at (0, x1) and increases at (x1, + 8)
How to judge whether a function is a periodic function and how to find its period?
For example: y = cos (X-2)
Judging by definition
As long as it is proved that f (x + T) = f (x)
So, t is the period
If the range of function y = LG (the square of AX + AX = 1) is r, find the range of real number a
1 when a = 0
Y = LG1
2 when a ≠ 0
Discriminant = a ^ 2-4a < 0 a (A-4) < 0 0 < a < 4
Comprehensive 1 2
0≤a＜4
Given the points (- 1, Y1), (2, Y2), (3, Y3) on the image with inverse scale function y = k ^ 2 + 1 / x, the following conclusions are correct
A.y1＞y2＞y3 B.y1＞y3＞y2 C.y3＞y1＞y2 D.y2＞y3＞y1
How to judge whether a function is periodic?
For example, is y = SiNx * cosx a periodic function
How to judge whether the result of multiplication or addition of two functions is a periodic function
1 periodic function plus periodic function or periodic function 2 periodic function plus aperiodic function is not periodic function 3 aperiodic function plus aperiodic function is not sure whether it is still periodic function 4 periodic function multiplied by periodic function or periodic function 5 periodic function multiplied by aperiodic function is not periodic function 6 non
If the value range of function y = LG (AX ^ 2-x + 1) is r, then the value range of a is?
When a = 0, it is the proper meaning; the range of function y = LG (AX ^ 2-x + 1) is r, and the key is that ax ^ 2-x + 1 can contain ax ^ 2-x + 1 ″ 0
When A0
Minimum a * (1 / 2a) ^ 2-1 / 2A + 1 = - 1 / 4A + 1
Let g (x) = ax ^ 2 + ax + 1,
The range of 〈 g (x) = ax ^ 2 + ax + 1 is [0, + ∞),
① When a = 0, G (x) = 1  a ≠ 0
② When a ≠ 0, G (x) = a (x + 1 / 2) ^ 2 + 1 - A / 4
∴a＞0 ， 1-a/4 ≤ 0 ∴a≥4
Hope to help you o (∩)_ ∩)O~
The range of y = LG (AX ^ 2-x + 1) is r
So ax is greater than X-1
Therefore, a > 0 and the minimum value of ax ^ 2-x + 1 is greater than 0
Therefore, when x = 1 / (2a), ax ^ 2-x + 1 = 1-1 / (4a) > 0
So, a > 1 / 4
If the range of function y = LG (AX & # 178; - x + 1) is r, then ax & # 178; - x + 1 ≥ 0 is included in R,
Let f (x) = ax & # 178; - x + 1,
The formula is f (x) = a (x-1 / (2a)), + 1-1 / (4a),
Then when A0, when x = 1-1 / (2a), take the minimum value of 1-1 / (4a) ≤ 0... To expand
If the range of function y = LG (AX & # 178; - x + 1) is r, then ax & # 178; - x + 1 ≥ 0 is included in R,
Let f (x) = ax & # 178; - x + 1,
The formula is f (x) = a (x-1 / (2a)), + 1-1 / (4a),
Then when A0, x = 1-1 / (2a), take the minimum value of 1-1 / (4a) ≤ 0, and deduce 0