Cho tam giác ABC vuông tại A, có AB=27cm, AC=36cm.

a) Tính số đo các góc nhọn trong tam giác ABC.

b) Vẽ đường thẳng vuông góc với đoạn thang BC tại điểm B, đường thẳng này cắt tia CA tại giao điểm D. Tính chiều dài AD.

c) Vẽ điểm E đối xứng với A qua đường thẳng BC. Không tính độ dài đoạn thẳng AE, CMR: 1/AE^2=1/4AB^2 + 1/4AC^2

d) Trên nửa mặt phẳng có bờ BC không chứa điểm A, lấy điểm M sao cho tam giác MBC vuông cân tại M. Chứng minh: AM là tia phân giác của góc BAC

Điểm kiểm tra một tiết môn Toán lớp 10A được cho ở bảng sau:

Tìm Mốt M 0 ?

A. 6

B. 8

C. 9

D. 10

Cho các số thực a, b, thỏa mãn a - b = 2 . Khẳng định nào sau đây là đúng?

Tích của hai số a và b:

A. có giá trị nhỏ nhất là -1

B. có giá trị lớn nhất là -1

C. có giá trị nhỏ nhất khi a = b

D. không có giá trị nhỏ nhất

Cho hàm số y = a x 3 + b x 2 + c x + d  có đồ thị như hình bên.

Khẳng định nào sau đây đúng?

A. a , d > 0 ; b , c < 0

B. a , b , d > 0 ; c < 0

C. a , c , d > 0 ; b < 0

D. a , b , c < 0 ; b , d > 0

Choose the word which has the underlined part pronounced differently from the rest.

A. hour

B. honest

C. vehicle

D. happy

Bất phương trình 3 2 x 2 + 4 x ≥ 3 4 x + 3 ?

A. x ≥ 3 hoặc  x ≤ − 1

B.  − 1 ≤ x ≤ 3

C.  x > 3  hoặc  x < − 1

D.  − 1 ; 3

Cho hai vectơ a →  và b →  khác 0 → . Xác định góc α giữa hai vectơ a →  và b →  khi  a → . b → = − a → . b → .

A.  α = 180 0 .               

B.  α = 0 0 .                 

C.  α = 90 0 .                    

D.  α = 45 0 .

Một hình chữ nhật có nữa chu vi là 28m. Chiều rộng kém chiều dài 12m. Tính diện tích của hình chữ nhật đó

Read the passage below and choose one correct answer for each question. Mr. and Mrs. Nelson have two children, Lara 10 and Peter is 16. Mrs. Nelson first discovered that Peter was getting into trouble when school rang her to say that he hadn’t turned up that day, or the day before. She realized right away that he had been truanting. Peter’s behaviour was causing conflict in the house and Mr. and Mrs. Nelson were both concerned. They had different views of how they should deal with Peter’s behaviour and this led to rows that upset the whole family. They decided to prevent Peter from going out with his friends, but this just made him more stubborn and he would continue to miss school and stay outside his curfew. Over the coming weeks, family life became more and more difficult. Mr. and Mrs. Nelson felt that they could no longer do this on their own and asked the school to help. The school arranged for Peter to talk to someone he trusted, and they made an agreement for him to start gradually attending school again. He was also given some time to catch up with the work he had missed. As he started to talk it through, Peter realized that he had been unhappy at school for a while. He admitted that he had felt lonely since his best friend moved away and another group of friends had persuaded him to skip school. As he missed more and more school, it became harder to go back. Peter was encouraged to tell his parents how much he missed his friend and that he wanted to spend time with his dad playing football or fishing. Mr. Nelson thought he had grown out of that a long time ago but was pleased to spend time with Peter again. Mr. and Mrs. Nelson tried to notice every day when Peter achieved his goal of attending school, being on time and remembering to do his homework. It took a little longer for Peter’s friendships to return to normal and Peter has had to leam to prove himself trustworthy to his parents, but gradually Mr. and Mrs. Nelson are learning to trust Peter again.

Question: The school applied all the following things to help Peter EXCEPT that ______.

A. they helped the Nelsons solve the problem on their own

B. they agreed to allow him to come back to school

C. they helped him to catch up with his study

D. they tried to make his communication with his friends better