A piece of, a loaf of, a bar of they all have the meaning of "one, one". What's the difference?

A piece of, a loaf of, a bar of they all have the meaning of "one, one". What's the difference?

A piece of
Such as a piece of paper
Loaf a loaf of bread
Bar, bar
What's the difference between a box of milk and a carton of milk?
Carton ['k а: T & # 601; n] n
The kid drink up a whole big carton of juice after play in the hot sun.
After playing in the hot sun, the children drank up a whole box of juice
Box means box
What are the verbs in the present continuous tense that go to e and add ing
leave,make,take,ride,pounce,practise,praise,refuse,restore,retire,brake,drive.
A problem of mathematical periodic function
It's not difficult. But I forgot
Let f (x) satisfy f (x + 2) 1 = 1 / F (x)
If f (x) = - 5
What is f [f (5)] = then
I forgot. Although there is an answer, I can't understand it. Who can explain it
F (x + 4) = 1 / F (x + 2) = f (x), so f (5) = - 5, and then inexplicably say: F [f (5)] = f (- 5) = f (3) = 1 / F (1) = - 1 / 5
I wonder, how can f (- 5) become f (3) all of a sudden? Who can explain it in detail? I know words + 30 points!
sorry.. I really forgot... That's the question... I've been thinking about it for two hours... For help...
If f (x + 4) = f (x), then f (x) has period T = 4, f (- 5) = f (- 5 + 4) = f (- 1) = f (- 1 + 4) = f (3)
That is to use f (x + 4) = f (x) continuously
You can change this f (x + 2) 1 = 1 / F (x) bit by bit and write it down. You have to do more math by yourself. You can't just listen to things.
F (x + 4) = f (x) brings in x = - 1
f(1)=f(-3)
F (x + 2) = f (X-2) brings in x = 3
f(5)=f(1)
therefore
F (- 5) = f (3) in fact, to put it bluntly, f (x + 4) = f (x) has a period of 4
-There are exactly two cycles between 5 and 3
f(-5)=1/f(-3)=f(-1)=1/f(1)=f(3)
Give me some points
Find out the verbs that need to be written in both the irregular verb list and the present progressive tense~
English verbs are made up of syllables. Syllables can be divided into stressed open syllables, stressed closed syllables, stressed r syllables, stressed re syllables and stressed letter combination syllables. In stressed closed syllables and stressed r syllables, if a word ends with a single consonant letter, it is necessary to double write and add ed or ing
When adding - ed / - ing, the last letter of the verb needs double writing
Admission
Ban Ban
To bolt; forbid
Bat batting
Beg, beg
Chat
Clap clap
Commit (a crime)
Control control
Dam, stop
Dip, dip
Dot embellishment
Pull, pull
Drop drop
Equipping
Fan fan , incite
Fit for
Hugs
Jam, jam
Jog
Human resource allocation
Mop (with a mop)
Nod nodded
Occurrence
Pat pat
Pin (with a pin)
Plan
Plug, plug
Prefer, prefer
Refer to
Regret, regret
Rob
Ship delivery
Shop shopping
Skip jump
Slip slip
Sob sobs
Spot out
Starring; embellishing
Step, step, step
Stop stop
To submit to; submit
Swap exchange
Tap, tap
Tip (tilt)
Top capping
Trap trap
Trip, trip, trip
Wag wag
Let the even function f (x) defined on R satisfy f (x + 1) + F (x) = 1, and if x ∈ [1,2], f (x) = 2-x, then f (8.5)=______ .
From F (x + 1) + F (x) = 1, take x = - x, get: F (1-x) + F (- x) = 1, because f (x) is even function, so f (1-x) + F (x) = 1, ②, ① - ② get: F (1 + x) = f (1-x), then take x = 1 + X, get f (2 + x) = f (- x) = f (x), so f (x) is a periodic function with period 2, so f (8.5) = f (8 + 0.5) = f (0.5) = f (- 2 + 0.5) = f (- 1.5) = f (1.5) ）And when x ∈ [1,2], f (x) = 2-x, so f (1.5) = 2-1.5 = 0.5, so f (8.5) = 0.5, so the answer is 0.5
Is it possible for most verbs to use the present continuous tense in the future?
No, only the words of position moving can be used to express the future. To give you a better way to remember, the following words are often used to express the future: come, come, go, start, finish, and die
Go, leave, start, arrive and so on are most commonly used
Here's an example,
He is coming to see you tomorrow morning.
We are going to play basketball this afternoon.
The train is starting in a few minutes
y=2cos(x/4+ π/3)-3sin(x- π/4)
y=sin(4x- π/3)-cos(3x+π/2)
This kind of minimum positive period (that is to say, the sum and difference of sine and cosine, and the coefficient of X is different, can not be calculated by formula)
It is to find the least common multiple of two minimum positive periods
For example, in 1, the two minimum positive periods are 8 π and 2 π respectively, so the minimum positive period of the function is 8 π;
2, the two minimum positive periods are π / 2 and 2 π / 3 respectively
The least common multiple of fractions 1 / 2 and 2 / 3 is the least common multiple 2 of the molecule divided by the greatest common divisor 1 of the line, so the minimum positive period of the function is still 2 π
The present continuous tense of English sentences
he is reading a book .
i am doing my homework .
mummy is cooking .
Im talking to you.
a car is running on the street.
they are building a new house.
Im watching TV.
You are looking at me.
What ah?
What are you asking? Do you want an example?
I am doing my homework at home.
I'm surfing the Internet.
On the problem of periodic function
If f (x) = f (X-2 (B-A)) is transformed into f (x) = f (x + 2 (a-b)), then is the period 2 (B-A) or 2 (a-b)
All of them are the same, generally taking the minimum positive period
Let t = 2 (a-b)
f(x)=f(x+t)
The period function is defined as D