How to use the and plural in English phrases?

How to use the and plural in English phrases?

The is a definite article, used to define
The plural is used for more than two
9、 Some special plural nouns and phrases 1. Leaf__________________ 2.life__________________
3.thief_________________ 4.knife_________________
5.shelf_________________ 6.half__________________
7.roof__________________ 8.German_______________
9.sheep_________________ 10.deer_________________
11.child________________ 12.woman teacher________
13.tooth________________ 14.foot_________________
15.people_______________ 16.postman______________
19.boy__________________ 20.key__________________
21.story________________ 22.family_______________
23.century______________ 24.baby_________________
26.tomato_______________ 27.potato_______________
28.radio________________ 29.zoo__________________
30.kilo_________________ 31.photo________________
32.businessman__________ 33.woman________________
34.man__________________ 35.difficulty___________
36.monkey_______________ 37.mouse________________
A
I don't know if I want this?
Simple algorithm of function period
Why sin2 (x + π) = sin2x
I don't quite understand. Can I work it out with the induction formula?
Sin2 (x + π) = sin [2x + 2 π] = sin [2x + 360] = sin2x
Multiply 2 into sin (2x + 2), ha ha, sorry, cell phone typing Sin is a function with a period of 2, which is equal to sin 2x
sin2（x+π）=sin[2x+2π]=sin2x
The period of sin function is 2 π, so sin (2x + 2 π) = sin 2x
How to understand that the definition range of logarithmic function is r
For example, G (x) = LG (2cx & # 178; + 2x + 1) if the range is r, what is △ and why?
X can take any real number
Y can also get any real number
If the range is r, then the range of F (x) = 2cx & # 178; + 2x + 1 must contain at least a set of positive numbers,
In this way, f (x) = 0 must have a real root (the discriminant is not less than 0), and C > = 0
If there are three points (- 4, Y1), (- 1, Y2), (2, Y3) on the image of function y = (- m ^ 2-4m-4) / X (M is a constant), then the size relationship of Y1, Y2, Y3 is
The answer is not sure. Why?
It is related to the value of M, and is discussed by classification
If the odd function y = f (x) defined on R satisfies f (x + 1) = - f (x), try to find the minimum number of zeros of this function in the interval [- 20082008]
The answer is 4017. I'd like to ask why it's not 2009. If you can explain it well, there are points
First of all, f (x) is an odd function defined on R, f (0) = 0, because f (x + 1) = - f (x), substituting x = 0, we get f (1) = 0, and because f (x + 1) = - f (x), we get that the function is a periodic function with a period of 2, so f (2) = 0. To sum up, the function values on all integral points on f (x) are equal to 0, and there are 4017 integer points in the interval [- 20082008], so there are 4017 zeros in the interval [- 20082008]
I hope it will help you
Because it is an odd function, f (0) = 0
F (x + 1) = - f (x) when x is an integer, f is 0
So (02008] has 2008 zeros and [- 2008,0) has 2008 zeros
Plus x = 0, there are 4017 points
If y = f (x) satisfies f (x + 1) = - f (x), the period is 2, so f (2,4,6) 2008)=0
Y = f (x) satisfies f (x + 1) = - f (x), the odd function f (0) = 0 defined on R, let x = 1, f (0 + 1) = - f (0) = 0, so f (1,3,5,7,9) 2007) = 0, a total of 2008, plus retelling, a total of 4016, plus f (0) = 04017
How to find the definition and range of logarithmic function
Y = log (a) (m) requires m to be greater than 0 and a to be greater than 0, i.e
Domain: (0, + ∞) range: real number set R
It's OK to understand these. This is the basis
If there are three points (- 1, Y1), (- 2, Y2), (3, Y3) on the image of the function y = - A & sup2; - 1 / X (a is a constant), then the size of Y1, Y2, Y3 of the function
Quick return in different ways
You can see it by drawing a picture
The period of F (x) = - f (x-3) is 6,
f(x)=-f(x-3)
Then f (x-3) = - f [(x-3) - 3] = - f (X-6)
So f (x) = f (X-6)
So t = 6
Definition field of logarithmic function range
Y = loga (x2-4x + 7) (a > 0 and a is not equal to 1)
x2-4x+7>0
Y belongs to R