Chứng minh ba điểm thẳng hàng hay
CM
a) ABOC và ABIO nội tiếp
B) AB^2 = AE.AD
C) Tia OI cắt BC tại F. Cm : FD tiếp tuyến đường tròn (O)
D) Vẽ đường kính EH (O) CM: B,I,H thẳng hàng
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Sen. Thom Tillis says he'll vote against Trump's national emergency
Sen. Thom Tillis will be among those Republican senators to vote in favor of a resolution against President Donald Trump’s declaration of a national emergency at the border, the North Carolina Republican made public Monday, increasing the chances that the resolution will be sent to the White House.Tillis, who is up for re-election in 2020, wrote in an op-ed for The Washington Post that while he favors border security, he is concerned the President has overreached with the national emergency declaration.“As a U.S. senator, I cannot justify providing the executive with more ways to bypass Congress,” he wrote. “As a conservative, I cannot endorse a precedent that I know future left-wing presidents will exploit to advance radical policies that will erode economic and individual freedoms.”
Republicans control 53 seats in the chamber. If all Democrats vote for it, they will still need four Republican votes to help them stop Trump’s national emergency declaration. They have two, now that Tillis and Maine Sen. Susan Collins, who’s also up for re-election in 2020, have said they’ll join.Other Republicans have also expressed concern about Trump’s decision to declare a national emergency as well.Sen. Lisa Murkowski, a moderate Republican from Alaska, told a home-state TV station that she would “probably” support the proposal of disapproval.“Not because I disagree with the President when it comes to border security, (or) certainly national security, but because I think it’s so important that there be clear lines when it comes to the separation of powers,” Murkowski told KTUU in Anchorage. “There’s going to be a great deal of debate as to whether or not the legal authority is there. I would suggest there probably is. The question is … is this over and above the authority that has been granted specifically to the Congress itself?”
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CHứng minh 3 điểm thẳng hàng của Anh Duy
a' Chứng minh: H là trung điểm của AC
b' Chứng minh: MC là tiếp tuyến của (O)
c' Trên tia đối của AC lấy điểm Q. Từ Q vẽ hai tiếp tuyến QD và QE của đuờng tròn (O) với D và E là hai tiếp điểm. Chứng minh ba điểm M, E và D thẳng hàng.
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Cho 2 đường tròn O,O’ CẮT nhau ở A,B (O Ó thuộc mặt phẳng A,B).Kẻ các đường kính góc BOC và góc BO’C. Chứng minh C,A,D thẳng hàng, Cho OO=5,OB=4,ÓB=3 tính diện tích tam giác BCD
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I have no words. Thank you, Taylor Swift. (She came, she sang, I’m dead)[Dads out here living their best lives.]
'If he slips, he falls. If he falls, he dies' -- Climbing 3,000 feet without ropes
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Smollett, Sandmann, Lara Logan are the three horsemen of the media apocalypse.
Amy Klobuchar allegedly mistreated staffers, sees difficulty getting team for 2020 run
During an interview with Fox News' Bret Baier last week, though, Klobuchar said she spoke with Reid, and “he doesn’t remember that and I don’t remember that either.”The New York Times published a story Friday detailing the harsh, occasionally demeaning manner in which 2020 presidential candidate Amy Klobuchar has treated her staff. There are a lot of disturbing details in the report, including accounts of Klobuchar throwing items "in the direction of aides" and making employees wash her dishes, which is probably unethical and definitely shitty.
The weirdest story, though, is about a comb. In 2008, an aide allegedly forgot to bring a fork for Klobuchar's salad aboard a short flight to South Carolina. According to the Times, Klobuchar "berated" the staffer for his mistake, then proceeded to eat the salad with a comb.
Yes, a comb. For hair!
From the Times:
What happened next was typical: Ms. Klobuchar berated her aide instantly for the slip-up. What happened after that was not: She pulled a comb from her bag and began eating the salad with it, according to four people familiar with the episode.
Then she handed the comb to her staff member with a directive: Clean it.It's natural for a tangle of questions to arise after reading news like this. Here are a few we're considering: What kind of comb did Klobuchar use to eat the salad? (A tail comb is likely because of its pointed end, but we do not know for sure.) We know she told the staffer to clean the comb after she was done eating, but did she clean the comb before she used it? What kind of salad was involved here? Was she able to spear a cherry tomato with that thing?Lot of news to COMB through today— Ira (@ira) February 22, 2019
"You heard me. Fetch the salad comb" pic.twitter.com/uc4ZSXq6gf— Hillary Busis (@hillibusterr) February 22, 2019
for what is a comb but a wide fork— Philip Bump (@pbump) February 22, 2019
anyone who had "salad comb" on their 2020 BINGO sheet please come collect your Porsche— JuanPa (@jpbrammer) February 22, 2019
people are like, "using a comb to eat a salad is trashbeast," but the reality is that using a comb to eat a salad is not trashbeast enough, truly to be a trashbeast is just to eat the salad with your hands— Elizabeth Bruenig (@ebruenig) February 22, 2019
Reports of Klobuchar mistreating staff started to circulate earlier this month, when HuffPost and BuzzFeed News published interviews with former staffers about her conduct. Klobuchar responded to those stories as she announced her presidential bid on February 10.
"Yes, I can be tough, and yes I can push people,” she said. “I have high expectations for myself, I have high expectations for the people that work for me, but I have high expectations for this country.”
To be clear, the comb anecdote is not the most important part of the reports on Klobuchar's behavior. Her treatment of employees, particularly her parental leave policy — which technically required employees to pay back their leave compensation if they didn't stay on staff long enough afterward — is genuine cause for concern.
It's not just an issue for 2020, either. These incidents should be interpreted, as Libby Watson wrote for Splinter last week, as "a story of a shitty boss and workers who deserve better" — the viral stories and the less Tweet-able allegations both.
And for the love of god, clean your comb fork before you use it.
But according to a Buzzfeed News report, numerous staffers said Klobuchar routinely sent late-night emails and berated subordinates over minor details and missteps. The report also said, "one aide was accidentally hit with a flying binder, according to someone who saw it happen, though the staffer said the senator did not intend to hit anyone with the binder when she threw it."
When asked about the report that she threw a binder, she did not flat-out deny it.
"I don't know, it's all anonymous. I will say that I'm proud of our staff," Klobuchar told Fox News last week. "And yes, I can be a tough boss, and push people -- that's obvious. But that's because I have high expectations of myself, I have high expectations of those who work for me, and I have a high expectation for our country. My chief of staff has worked for me for six years, my state director for seven years, my campaign manager for 14 years."
Asked specifically whether she had thrown a binder at someone, Klobuchar responded: "If you look at that story, I think you'll see it said something about me throwing a binder down -- not at somebody," Klobuchar said. "I just know that I should be judged, and I will take responsibility for, everything that happens on this campaign."
Some critics have charged that the criticism over Klobuchar's behavior is sexist, suggesting male managers often are not challenged for a tough management style.
A campaign spokeswoman told the Times: “The senator has repeatedly acknowledged that she can be tough and push people hard. But these anonymous stories — some of which are just plain ridiculous — do not overshadow the countless experiences of people on the senator’s team who she has been so proud to work with.”
Klobuchar announced earlier this month that she would join the crowded field of Democratic candidates lining up to take on President Trump in 2020.
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See the Galaxy Fold, Samsung's new foldable phone
Samsung unveiled the Galaxy Fold, a phone that opens into a tablet. See its new features and hefty pricetag.
See Also: 6 major challenges foldable phones need to overcome to prove they're not a fad
Foldable phones are really, finally, happening this year. But almost nobody should buy one until their many kinks are worked out.Earlier this week, Samsung upstaged its own Galaxy S10 unveiling (all four of them) with another big announcement: its foldable Galaxy Fold phone. The nearly $2,000 luxury device, which transforms from a phone into a tablet when unfolded, is being touted as a taste of the future of mobile.But now that we're days removed from the Galaxy Fold's flashy reveal and merely days away from Mobile World Congress, where a handful of other Chinese phone-makers will show off their own foldable phones, I can't help but see red flags everywhere.In 2017, I made a prediction that foldable phones had no chance of succeeding. At the time, I based my skepticism off of prototype foldable displays and the many dual-screen and foldable phones that failed to catch on.The short of it was this: the technology to make foldable phones practical isn't ready yet And now, even without seeing the Galaxy Fold in person, I'm more certain than ever foldable phones are going to be a short-lived fad.That Samsung didn't feel confident enough to let any journalists try out the Galaxy Fold for themselves, especially when the device is launching in two months, is somewhat alarming.The fact is, foldable phones are cool to look at and they're exciting to write about — it sure beats writing about another well-made Samsung knockoff that costs hundreds less — but there are clear engineering challenges that still need to be overcome for foldable phones to really herald in a new era of mobile. Solutions that not even Samsung has figured out yet.If foldable phones are ever to become mainstream, all of the following need to be solved.
1. The crease
There's no getting around the crease when you fold a screen in half. From afar, the crease running down the middle of the fully-opened display on the Galaxy Fold is hardly visible. But up close, which is how you'll be using it, you'll definitely see it. And once you do, you won't be able to unsee it.Every foldable display I've seen has a crease. There's no way to get around it, and I don't foresee any company solving this problem anytime soon. Just as there's a visible crease when you fold a piece of paper in half, the crease on foldable phone screens will be a constant reminder that you're essentially using a prototype.It’s a little difficult to make out but there’s a visible crease where the hinge is on the Galaxy Fold #Unpacked2019 pic.twitter.com/QG2OyCRHjx— Karissa Bell (@karissabe) February 20, 2019
2. The durability
With the crease comes the question of durability. Samsung was super gung-ho about the hinge on the Galaxy Fold. Don't get me wrong, it looks like the most beautiful hinge on a foldable screen so far (unlike the hideous wrinkly bend on the Royole FlexPai), but how many unfolds will it be able to endure? How durable is a display that you'll fold and unfold hundreds of times a day?
It's bad enough to have a single dead pixel on a screen on a $1,000 phone. What happens if the pixels along the crease start to die? Can any phone maker guarantee the pixels along a screen's crease will be good for years to come?
What about using a case? How does a case work on a foldable phone?
3. The software
Man, oh, man is the software for foldable phones not ready. Sure, Google has already thrown its full support for Android on foldable devices, but that doesn't mean squat. If the spectacular failure of Android tablets has taught us anything, it's that third-party developer support is extremely crucial to a form factor's success.
Getting developers to optimize their apps for a foldable phone's specific aspect ratio is going to be a tough challenge. It's hard enough that app developers already have to design their apps for a million different screen sizes and aspect ratios on Android, and now phone makers want them to do it again? Good luck with that.At least with regular phones, there are already established display aspect ratios everyone agrees on. Foldable devices, not so much. Take the Galaxy Fold: It has an outside display with a 21:9 aspect ratio and unfolded interior display with 4.2:3 aspect ratio. Neither of these are commonplace, and that's just for Samsung's phones.Who even knows what aspect ratios Xiaomi's foldable phone (above) with two folds or Huawei's yet-to-be-seen device has.
How many developers will actually update their apps for tablets? I mean, it's been almost nine years, and Instagram still doesn't have a tablet app for iPad or Android tablets. What makes device makers think developers will suddenly come around to making tablet apps again?
4. The battery life
Phones just started getting big enough batteries to last almost two days and now you wanna take a step back all because you want a slightly larger, creased screen? Thanks, but no thanks.
I'm curious to see how long the Galaxy Fold's 4,380 mAh battery will last when using the expanded interior screen. A 4,380 mAh battery may seem like a lot for a normal phone, but for a 7.3-inch screen, it sounds wimpy; Samsung's new Galaxy Tab S5e has a 10.5 inch screen, and it needs a 7,040 mAh battery. To put that into even greater perspective, Samsung's upcoming Galaxy S10 5G has a 4,500 mAh battery and it has a 6.7-inch screen.
What I'm saying is: battery life is gonna be an issue with these early foldable phones. Constantly unfolding and folding a screen is only gonna eat battery faster.
Either we get shorter battery life with smaller cells or phone makers cram bigger batteries and make the foldable phone even thicker. Ugh.
5. The thickness
Samsung hasn't disclosed dimensions for the Galaxy Fold, but you don't need to be a rocket scientist to see it's thicc when folded up. You can easily get an idea of how thick the Fold is by looking at the USB-C port then doubling it.
A thick phone is acceptable if it means having like a massive 16,000 mAh battery that'll last up to five days on a single charge. But otherwise, why would anyone choose to put a brick in their pants? Foldable phones need to get significantly thinner before they're worth owning.
6. The price
Samsung's Galaxy Fold will cost $1,980 when it comes out on April 26.
That. Is. An. Insane. Amount. Of. Money.
And if Samsung thinks it can charge nearly $2,000 for a foldable phone, you can bet your lunch money Huawei and Oppo and Xiaomi won't be shy doing the same. Although Chinese phone makers are known for undercutting Samsung and Apple on pricing, they've not shied away from selling their own exorbitantly-priced phones under the guise of offering a luxury experience.
Samsung's set expectations with the Galaxy Fold, calling it a luxurious device that's designed for early adopters, but if it or any other device maker wants foldable phones to be the next big thing in mobile, prices will have to come down. Like way down. Foldable phones stand no chance if few people can afford them.
Breakthroughs at MWC 2019?
Just because Samsung hasn't figured out how to overcome these challenges doesn't mean another company hasn't.
At Mobile World Congress, we'll finally get a look at how other companies will tackle foldable phones. Will they succeed where Samsung hasn't?
I'd love to see a company prove me wrong and show me a foldable phone that has all of these issues covered. But it seems unlikely that'll happen at MWC this year. We'll probably see a bunch of head-turning prototypes, but that'll likely be it.
BY MASH' RAYMOND WONG
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Great snakes! This rattler was taken from a man in Jax Beach carrying it around and claiming to be an "agent of god." Police had him toss it in a squad car, and called FWC to capture it.
Well, meanwhile in Jacksonville Beach this morning.... 6, 7, or 8 feet?
I'm not getting the tape measure out. Thank you to the Florida Fish
and Wildlife Commission for relocating our guest.
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Andrew Napolitano says if NYT report is true, Trump may have attempted obstruction
ĐỀ CƯƠNG ÔN TẬP HỌC KÌ II - Môn Toán 10 - TRƯỜNG THPT CHU VĂN AN
SỞ GIÁO DỤC VÀ ĐÀO TẠO HÀ NỘI TRƯỜNG THPT CHU VĂN AN __________________
|
ĐỀ CƯƠNG ÔN TẬP HỌC KÌ II NĂM HỌC 2015-2016 Môn: Toán Khối lớp:10 - Chương trình: Nâng cao |
NỘI DUNG CHÍNH
ĐỀ 01
Bài 1 (1 điểm). Tìm tập xác định hàm
số
Bài 2 (3,5 điểm).
1. Giải các bất phương trình sau
a)
b)
2.
Xác
định giá trị tham số để
hệ bất phương trình
vô nghiệm
Bài 3 (2 điểm).
1.
Cho biết Tính
các giá trị lượng giác còn lại của góc
2.
Rút gọn
biểu thức
Bài 4 (3 điểm).
Trong mặt phẳng toạ độ cho
đường thẳng
và
đường thẳng
1.
Xét vị trí
tương đối của
2.
Xác
định vị trí điểm sao cho
khoảng cách từ
đến
bằng
3.
Lập
phương trình đường tròn đi qua và
tiếp xúc hai đường thẳng
Bài 5 (0,5 điểm). Cho là các số
thực thoả mãn :
Tìm giá trị
lớn nhất, giá trị nhỏ nhất của biểu
thức
ĐỀ 02
Bài 1(2,5 điểm). Giải các bất phương trình sau
1.
2.
Bài 2 (2 điểm).
1.
Tìm các giá
trị của tham số sao cho hàm
số
xác
định trên
2.
Giải bất
phương trình
Bài 3 (1,5 điểm).
1.
Tính
2.
Chứng minh
đẳng thức sau không phụ thuộc vào
Bài 4 (3,5 điểm).
1.
Trong mặt
phẳng toạ độ cho họ đường
cong
Chứng tỏ rằng họ là họ
các đường tròn. Xác định tâm và bán kính
đường tròn có bán kính nhỏ nhất trong họ
2.
Trong mặt
phẳng toạ độ cho tam giác
có
đường
cao
Điểm
thuộc
đường thẳng
a)
Xác
định toạ độ các đỉnh tam giác Tính
diện tích tam giác
b)
Xác định
phương trình đường tròn ngoại tiếp tam
giác
Bài 5 (0,5 điểm). Cho thoả mãn
Chứng minh rằng
ĐỀ 03
Bài 1 (1,5 điểm). Giải bất phương
trình
Bài 2 (2,5 điểm).
1.
Giải
hệ bất phương trình
2.
Cho hàm số
(
là
tham số)
a)
Xác
định sao cho
với
mọi
b)
Xác
định sao cho bất
phương trình
vô nghiệm.
Bài 3 (2 điểm).
1.
Cho góc thoả
mãn
Tính giá trị
của biểu thức
2.
Chứng minh
đẳng thức
Bài
4 (3,5 điểm). Trong mặt phẳng toạ
độ cho
đường tròn
có
phương trình
và điểm
1.
Chứng
tỏ nằm ngoài
đường tròn. Lập phương trình tiếp
tuyến với đường tròn biết tiếp
tuyến đi qua điểm
2.
Lập
phương trình đường tròn đối xứng
đường tròn qua
đường thẳng
3.
Tính diện
tích tam giác đều nội
tiếp đường tròn
4.
Lập
phương trình đường thẳng đi qua
điểm và cắt
đường tròn
tại hai
điểm phân biệt
sao cho
Bài 5 (0,5 điểm). Tìm các giá trị thỏa
mãn bất phương trình:
ĐỀ 04
Bài 1(2,5 điểm). Cho bất phương
trình (
là
tham số)
1. Giải bất phương trình (1)
với
2. Xác định sao cho bất
phương trình
nghiệm
đúng với mọi
Bài 2 (2,5 điểm).
1. Giải bất phương trình
2. Xác định sao cho hệ
bất phuơng trình
có nghiệm
duy nhất.
Bài 3 (1,5 điểm).
1. Cho tam giác Chứng minh
rằng
2. Chứng minh rằng
Bài 4 (3 điểm). Trong mặt phẳng
toạ độ cho hình bình hành
,đỉnh
và
là hình
chiếu của
trên
1. Lập phương trình các đường
thẳng
2. Xác định toạ độ các
đỉnh
3. Xác định vị trí điểm sao
cho
đạt giá
trị bé nhất .
Bài 5.(0,5 điểm). Tìm giá trị nhỏ
nhất của hàm số
ĐỀ 05
Bài 1 (1,5 điểm). Giải hệ bất
phương trình
Bài 2 (3 điểm).
1. Giải bất phương trình
2. Xác định để
mọi
đều là
nghiệm của bất phương trình
Bài 3 (1,5 điểm).
1. Cho biết Tính giá trị
biểu thức
2. Rút gọn biểu thức
Bài 4 (3,5 điểm). Trong mặt phẳng
toạ độ cho các
đường thẳng
và điểm
1. Xác định toạ độ
điểm sao cho
đạt
giá trị bé nhất.
2. Viết phương trình
đường thẳng đối
xứng
qua
3. Viết phương trình
đường thẳng cắt
tại
sao cho tam giác
vuông
cân tại
4. Lập phương trình
đường tròn có tâm
và
cắt đường thẳng
tại hai
điểm phân biệt
sao cho diện
tích tam giác
bằng
.
Bài 5 (0,5điểm). Tam giác có
đặc điểm gì nếu
(Với
là
3 cạnh tam giác và
là diện tích
tam giác
ĐỀ 06
Bài 1.(1,5 điểm) Cho ,
là
tham số.
1.Xác định giá trị sao cho
đúng
với mọi
.
2. Xác định giá trị sao cho phương
trình
có hai
nghiệm trái dấu.
Bài 2.(3 điểm) Giải bất phương trình sau
1. 2.
.
Bài 3.(1,5điểm)
1.Cho biết . Tính giá
trị biểu thức
.
2.Chứng minh rằng: vuông nếu
.
Bài 4 (3,5 điểm). Trong mặt phẳng
toạ độ ,cho
1. Xác định các tiêu điểm,tiêu cự
,tâm sai,toạ
độ các đỉnh,độ dài các trục của
.Vẽ
(E).
2. Xác định vị trí điểm biết
3. Tìm điểm biết
.
Bài 5.(0,5 điểm). Tìm giá trị tham số sao
cho bất phương trình
nghiệm
đúng với mọi
.
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