youi lko phak obq ske
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) Do PQ = QA (gt)
⇒ Q là trung điểm của AP
Tứ giác PHAK có:
Q là trung điểm của AP (cmt)
Q là trung điểm của HK (gt)
⇒ PHAK là hình bình hành
b) Do PHAK là hình bình hành (cmt)
⇒ PK = AH
c) ∆HNK vuông tại N
Q là trung điểm của HK (gt)
⇒ NQ là đường trung tuyến ứng với cạnh huyền HK
⇒ NQ = HK : 2 (1)
∆HMK vuông tại M
Q là trung điểm HK (gt)
⇒ MQ là đường trung tuyến ứng với cạnh huyền HK
⇒ MQ = HK : 2 (2)
Từ (1) và (2) ⇒ MQ = NQ
∆MNQ có:
MQ = NQ (cmt)
⇒ ∆MNQ cân tại Q
1. "Don't forget to phone the office"she told him
She reminded him not to forget to phone the office
2. I'm afraid I haven't got time to listen to you
I wish I had time listen to you
3. The police has just released John
John has just been released by the police
4. I couldn't hear them because they were speaking too softly
They were speaking too softly that I couldn't hear them
5. We spent five hours getting to London
It took us 5 hours toget to London
6. She doesn't usually stay up so late
She's not used ..to staying up so late
7. If I were you I'd look for another job.
I suggest that you look for another job.
8. He lost his money simply because he wasn't careful
If he had been careful, he wouldn't have lost his money simply
9. They last visited me five years ago
They haven't ..visited me for 5 years
10. All his suits were made in Paris
He had all his suits made in Paris
Cho hinh ve biet xy song song voi pq, goc OAy = 50°, goc AOB = 90°. Hay tinh goc OBq
Không thấy hình vẽ đâu cả
7/ " Have you seen my gloves , Lan "
- Thomas asked Lan if she had seen his gloves.
8/ " What do you want for dinner tonight , Ly "
He asked Ly what she wanted for dinner that night.
9/ " Open the door , " he said to them
He told them to open the door.
10/ I'm sorry I don't have time to go to the cinema with you
I wish I had time to go to the cinema with you.
11/ It's a pity John can't come to my birthday party this weekend
John wish he could come to my birthday party that weekend.
12/ It's a pity they are having a class at the moment
They wish they weren't having a class at the moment.
13/ It's a pity MY school doesn't organize outdoor activities
I wish MY school organized outdoor activities.
14/ They often went to school by bike when they were young
They used to go to school by bike when they were young.
15/ He doesn't have meals with his family any more
He used to have meals with his family.
18/ Dennis gave up smoking three years ago
Dennis used to smoke three years ago.
19/ My brother had his hair cut short when he joined the army
My brother used to have his hair cut short when he joined the army.
20/ He feels sorry that the can't come to his brother's wedding
I wish he could come to his brother's wedding.
21/ She's sorry she can't play the piano
I wish she could play the piano.
Đáp án B
Gọi hàm số cần tìm là y= ax+ b.
Đường thẳng d cắt trục Ox tại và cắt Oy tại Q(0; b) với a<0 và b> 0
Suy ra
Ta có d đi qua M nên 2= a+b hay b= 2-a thay vào (3) ta được
Áp dụng bất đẳng thức côsi ta có
Đẳng thức xảy ra khi và chỉ khi
Vậy hàm số cần tìm là y= -2x+ 4.
cc