\(sinx-cosx=4sinxcos^2x\)

Cho A(1;5) B(-2;2) \(\overrightarrow{v}\)(-3;1)

Tìm ảnh của AB qua \(T_{\overrightarrow{v}}\)

giải phương trình\(\sqrt{3}cos\left(x+\dfrac{\Pi}{2}\right)+sin\left(x-\dfrac{\Pi}{2}\right)=2sin2x\)

Chia động từ theo thì quá khứ hoàn thành tiếp diễn hoặc thì quá khứ tiếp diễn

1) Jim was on his hands and knees on the floor. He (look)…………………….…….for his cigarette lighter.

2) We (walk)……………………………………...along the road for about 20 minutes before a car stopped and the driver offered us a lift.

3) When I arrived, everyone was sitting round the table with their mouths full. They (eat)…………………………….………….

4) When I arrived, everyone was sitting round the table and talking. Their mouths were empty but their stomachs were full. They (eat)…………………………………………………..…….

5) Ann (wait)…………………………………..for me when I came. She was rather annoyed with me because I was late and she (wait)………………………..…for a long time

1: Chọn câu có nghĩa tương đương với nghĩa của câu đã cho

1. We had had breakfast when I left home.

A. I left home and I ate nothing. B. I ate breakfast and then I left home.

2. By the time you came, I had read this book.

A. You came and then I read this book. B. I read this book before you came.

3. She danced after she had finished her work.

A. She didn't finish her work, but she still danced. B. She finished her work and then she danced.

4. I didn't do it before he had agreed.

A. I did it after he agreed. B. I did it before he agreed.

5. She hated me by the time I told that I liked him.

A. I told her that I liked him, and then she hated me. B. She hated me before I told that I liked him.

Số vị trí biểu diễn các nghiệm của phương trình : \(4cos^2x-4cosx-3=0\) trên đường tròn lượng giác là ?

A . 2

B . 0

C . 1

D . 4

giải phương trình 1) \(\dfrac{cos2x}{1-sin2x}=0\)

2) tan3x=tan4x

3) cot2x.sin3x=0