Sáng kiến kinh nghiệm Một số kỹ thuật truyền cảm hứng học môn Toán bằng tiếng anh cho học sinh lớp 10
Thực hiện Đề án ngoại ngữ quốc gia năm 2020 nhằm đổi mới toàn diện việc
dạy và học ngoại ngữ trong hệ thống giáo dục quốc dân, triển khai chương trình
dạy học và học ngoại ngữ mới ở các cấp học, trình độ đào tạo, nhằm đạt một bước
tiến rõ rệt về trình độ, năng lực sử dụng ngoại ngữ của nguồn năng lực, nhất là đối
với một số lĩnh vực ưu tiên. Hiện nay, các trường học, lớp học theo mô hình dạy
học song ngữ đang
phát triển rất nhanh do nhận thấy các vấn đề cấp thiết này. Một
trong các môn học được ưu tiên thử nghiệm đầu tiên đó là dạy học Toán song
ngữ Anh – Việt bởi hai lí do. Thứ nhất, tiếng Anh là ngôn ngữ phổ biến nhất để
giao tiếp trên thế giới. Thứ hai, Toán học là môn học có ngôn ngữ rõ ràng, trong
sáng và tương đối đơn giản. Học sinh không cần phải mất nhiều thời gian mà vẫn
có đủ vốn từ để có thể theo học. Hơn nữa học Toán là học cách tư duy, học Toán
bằng tiếng Anh là học cách tư duy trực tiếp bằng tiếng Anh. Học Toán (và các môn
khác) bằng tiếng Anh là thực hiện nguyên tắc học ngoại ngữ “Learning English
through usage” (học tiếng Anh qua sử dụng tiếng). Cách học này nhằm khắc
phục nhược điểm “học nhưng không sử dụng được” của một bộ phận lớn người
học ở nước ta, đưa tiếng Anh từ ngoại ngữ (foreign language) trở thành ngôn ngữ
thứ hai (second language).
Tóm tắt nội dung tài liệu: Sáng kiến kinh nghiệm Một số kỹ thuật truyền cảm hứng học môn Toán bằng tiếng anh cho học sinh lớp 10

học bình thường cần phải học ở trường G. Không thấy việc học toán bằng tiếng Anh là cần thiết Câu hỏi 3: Theo em chương trình học toán bằng tiếng Anh nào sau đây là phù hợp? A. Chương trình Toán của Việt Nam dịch ra tiếng Anh B. Chương trình của các nước tiên tiến C. Chương trình được soạn riêng mà tích hợp môn Toán, môn tiếng Anh và môn chuyên Câu hỏi 4: Thời gian học toán bằng tiếng Anh trong 1 tuần? A. 1 tiết B. 2 tiết C. 3 tiết D. 4 tiết Câu hỏi 5: Khó khăn khi học toán bằng tiếng Anh? A. Trình độ tiếng Anh giáo viên chưa cao B. Trình độ tiếng Anh học sinh chưa cao C. Nội dung chương trình dạy và học toán bằng tiếng Anh chưa có Câu hỏi 6: Khó khăn khi học từ vựng toán bằng tiếng Anh A. Từ chuyên ngành chỉ gặp trong tài liệu toán nên khó nhớ B. Một từ có nhiều nghĩa C. Nhiều từ có cùng một nghĩa D. Là một cụm từ để diễn đạt khái niệm toán học E. Một khái niệm toán học có thể diễn đạt theo nhiều cách khác nhau F. Nghĩa của từ vựng trong toán học khác với nghĩa thông thường. Câu hỏi 7: Em có thích học Toán bằng tiếng Anh không? A. Rất thích B. Thích C. Bình thường D. Không thích Xin chân thành cảm ơn các em ! dPHỤC LỤC 2 LESSON PLAN 1 PARAMETRIC EQUATIONS OF A LINE I. Lesson’s objectives. At the end of the lesson, the students will be able to: - Prove the parametric equations of a line. - Identify the direction vector and the coordinates of points of a line with given equation. - Find the parametric equations of a line with given conditions. - Solve problems involving lines. II. Subject Matter - Reference: Geometry for High-school Textbook. - Materials: Sheets of paper. III. Procedure T: teacher; S: Student; Q: questions; Ans: Answer ; Contents Teacher and Students’activities 1. Introduce the lesson I. Direction vector of a line u r Definition: A non –zero vector u r is a direction vector of a line d if the line containing n is parallel or coincident to d. Notes: - A given line has infinitely direction vectors which are collinear. (i.e: if u r is a direction vector of a line d then k. u r is also direction vector of the line (for any non –zero scalar k). T: State the definition of direction vector of a line Q: How many direction vector does a line have? What is the relation between them? - A non-zero vector u r is a direction vector of infinitely parallel lines. - Given a point M and a direction vector u r , there is one and only one line passing through M and get u r be direction vector. Problem: Given the line d passing through a point ( )0 0 0;M x y and get a non-zero vector u = r (a; b) be a direction vector. What is the condition for the point M(x; y) to lie on the line d? Solution: M dÎ if 0M M uuuuuur and u r are collinear, it means there exists a parameter t such that 0M M tu= uuuuuur r , then we have ( ) ( )0 0; ;x x y y t a b- - = 0 0 x x at y y bt = +ì Û í = +î II. Theorem The point M(x; y) is on the line d if and only if there exists a number t such that ( )0 0 x x at t R y y bt = +ì Û Îí = +î The system above is called the parametric equations ofthe line d, and t is called the parameter. Note: - Each point on the line corresponds to exactly one value of t. - By equating t values, we obtain the equation 0 0x x y y a b - - = We call this equation the Cartesian equation of the line. - The gradient of the line b a How many lines does a vector be direction vector of? Why? S:Answer all the questions T:State the problem S: Find the solutions. Q:What is the relation between 0M M uuuuuur and u r if M lies on the line d? Which vector equality can we deduce? T:State the parametric equations of a line officially. Q.How do we calculate the gradient of the line? 2. Examples Example 1: Given a line din the form of T: Deliver the parametric equations ( )2 3 4 5 x t t R y t = +ì Îí = - +î and a point M( -3 ; 6) a) State the coordinates of a direction vector of dand two points on d. Explain? b) Find the parametric equations of the line 1d passing through the point M and being parallel to the line d. c) Convert to Cartesian form. Answer: a) A direction vector of d is u = r (3; 5) To obtain the points on the line d, we substitute t by a real number. Let t = 1, we get the point (5;1) Let t = 0, we get the point (2;-4). b) Two parallel line have direction vectors in common, then a direction vector of 1d is (3; 5). Because the line 1d passes through the point M then the parametric equations of the line 1d is ( )3 3 6 5 x t t R y t = - +ì Îí = +î c) The Cartesian form of the line 2 4 3 5 x y- + = Example 2: Find the parametric equations of the line d passing through the points A(1; 2) and B(2;1). Answer: The line d passing through the points A and B then it has direction vector AB = uuur (1; -3). Then the parametric equations of the line d is ( )1 2 3 x t t R y t = +ì Îí = -î worksheet containing with problems. S: Find the solution to the problem T:Is the parametric equations form of a line unique? Why? 3. Summary the lesson - Review the terms learned during the lesson. - Summary the knowledge focus 4. Homework Exercise 1:Find the parametric equations of the line which passing through (3; -4) and is parallel to the line ( )1 2 2 x t t R y t = +ì Îí = -î Exercise 2: (k; 4) lies on the line with parametric equations ( )1 2 1 x t t R y t = -ì Îí = +î . Find k. Exercise 3: Given the line ( )2 1 2 x t t R y t = +ì Îí = -î and the point A(1; 1). Prove that A doesn’t lie on the line and find the coordinates of the foot of perpendicular of A on d. Exercise 4: Yacht A moves according to ( )4 5 2 x t t R y t = +ì Îí = -î Where the distance units are kilometers and the time units are hours. Yacht B moves according to ( )1 2 8 x t t R y t = +ì Îí = - +î a. Find the initial position of each yacht. b. Show that the speed of each yacht is constant and state the speeds. c. If they start at 6:00am, find the time when the yachts are closest to each other. d. Prove that the paths of the yachts are right angles to each other. LESSON PLAN 2 EQUATION OF CIRCLE I. Lesson’s objectives. At the end of the lesson, the students will be able to: - Recognize the equation of a circle (the standard form and the general form). - Prove the equation of a circle. - Find the equation of a circle with given conditions. - Solve problems involving circles. II.Subject Matter - Reference: Geometry for High-school Textbook. - Materials: Sheets of paper, Protractor, Puzzles. III. Procedure Contents Teacher and Students’ activities 1. Introducing terms used in the lesson (C): circle I: center of the circle B, C, D: points on the circle IB: radius of the circle (a line segment joining the center of the circle to any point on the circle itself; or the length of such a segment, which is half a diameter). R: the length of the radius T: Deliver the 1st worksheet to ask the students to fill in the name of objects in a given picture. S: Work in pairto finish the task in 3 mins. T: correct the answers. (C) R k I B C D k: tangent line of the circle (a straight line that touches the circle at a single point). CD: chord (a line segment whose endpoints lie on the circle). CmD: minor arc (connectedpart of the circle's circumference). Line CD: Secant(an extended chord, a straight line cutting the circle at two points). 2. Reading the passage to getacquainted with the language Fill in the gaps using the given words (a word may be used one more time) radius distance tangent points centre Common A circle is the set of all (1) in a plane that are a given (2) from a given point, the (3). The distance between any of the points and the centre is called the(4). A(5) of a circle touches the circle at one point and the distance from the center of the circle to the tangent is equal to the radius of the circle. T: deliver the 2st worksheet to the students. S: Work in pair to finish the task in 3 mins T: correct the answer and take note some sentences that should learn by heart “the distance from.to” “to be equal to” 3. Introduce the lesson Problem 1. In the coordinate plane, given a point I(a; b) and a positive real number R. On what conditions that the point M(x; y) is on the circle C(I; R) ? Solution: M is on the circle if and only if the distance from the point M to the point I is equal to R, that is IM R IM R= Û = uuur ( ) ( )2 2x a y b RÛ - + - = ( ) ( )2 2 2x a y b RÛ - + - = I. Standard form of the equation of a circle T: State problem S: Find the solution to the problem Q: What is the formulae to calculate the distance between two points? What is the coordinates of the vector IM? The circle with center I(a; b) and radius R is the set of all points (x;y) satisfying the equation ( ) ( )2 2 2 (1)x a y b R- + - = The equation (1) is called the Standard form of the equation of a circle Example 1. Determine the coordinate of the center and the radius of a circle in the following cases: i) ( ) ( )2 22 1 3x y- + + = ii) ( )22 1 4 0x y+ + - = iii) 2 2 4 2 1 0x y x y+ - - + = iv) 2 2 4 2 6 0x y x y+ - - + = Answer: i) ( )2; 1 ; 3I R- = ii) ( )0; 1 ; 2I R- = iii) Completing the square form of x and y, we obtain ( ) ( )2 22 1 4x y- + - = Then ( )2;1I and 2R = iv) ( ) ( )2 22 1 1x y- + - = - then this is not the equation of a circle Problem 2. Given the equation ( )2 2 2 2 0 2x y ax by c+ - - + = On what conditions does the equation (2) be the equation of a circle. In this case, determine the coordinates of the center and the formula to calculate the radius. Solution:Write the left-hand sideof the equation (2) in completed square form ( ) ( )2 2 2 2 0x a y b a b c- + - - - + = Moving on the constant to the right-hand side ( ) ( )2 2 2 2x a y b a b c- + - = + - The equation (3) is in the standard form of a T. State the equation of a circle officially. T. Deliver the 3rd Worksheet. S. Finish the task individually. T. Correct the answer. Q. Convert the given equation to the standard form to identify the coordinates of the center and the radius in each cases. Q. Completing the squares and moving on the constant to the right S.Convert the given equation to the standard form of equation. State the condition that the equation exist. Then,Identify the coordinates of the center circle, the equation exits if and only if the right- hand side is positive, that is 2 2 0a b c+ - > . In this case, the coordinates of the center are (a; b) and the radius is 2 2a b c+ - II. General equation of a Circle The equation 2 2 2 2 0x y ax by c+ - - + = When 2 2 0a b c+ - > , is the general equation of a circle with center I(a; b) and the radius of the circle is 2 2R a b c= + - and the length of the radius in this case T. Correct the answer and state the general equation of a circle officially. 4. Examples Example 1. Given two points A(1; 2) and B( -1; 4). Find the equation of the circle with the diameter AB. Answer: The center of the circle is the midpoint I of the segment AB, then the coordinates of I(0; 3) and the radius 2R IA= = . Hence, the equation of the circle with the diameter AB is ( )22 3 3x y+ - = Example 2.Given three points A(1;2); B(2;5); C(4;1). Find the equation of the circumcircle of the triangle ABC. Answer: T. Deliver the 4rd worksheet. S.Finish the task in 5 mins. T.Correct the answer. Q. What is the center of the circle? How to calculate the coordinates of the midpoint of a segment? ( )1;3AB = uuur ; ( )2; 4BC = - uuur ; ( )3; 1AC = - uuur Notice that . 0AB AC = uuur uuur then the triangle ABC is right triangle at A. Hence, the center of the circumcircle is the midpoint of the hypotenuse BC. So, the center I(3; 3) and the radius 5R = and the equation of the circle is ( ) ( )2 23 3 5x y- + - = Example 3.Find the equation of a circle which touches the x-and y-axes and passes through the point A( -1; 3) Answer: Let I be the center of the circle with coordinates (a; b).The circle touches the x and y –axes that means d(I;Ox) = d(I; Oy) then a b R= = Case 1: If a = b then we obtain the equation ( ) ( )2 2 2x a y a a- + - = The point A is on the circle then the coordinates satisfying the equation, then we have the equation ( ) ( )2 2 2 21 3 4 10 0a a a a a- - + - = Û - + = The equation has no roots in this case. Case 2: If a = -b then the equation is ( ) ( )2 2 2x a y a a- + + = The point A is on the circle then the coordinates satisfying the equation, we obtain the equation ( ) ( )2 2 21 3a a a+ + + = 2 8 10 0a aÛ + + = Solving this equation gives 4 6a = - ± .Therefore the solution is ( ) ( ) ( )2 2 24 6 4 6 4 6x y+ + + - - = - - Notice the character of the triangle? Locate the center of a right triangle. Under what condition that a line touchesa circle? ( ) ( ) ( )2 2 24 6 4 6 4 6x y+ - + - + = - + 5. Summary the lesson - Review the terms learned during the lesson through flashcards. - Summary the knowledge focus 6. Homework Exercise 1:Find the equation of the circle (C) centered at I(1; 2) and tangent to the line (d) with the equation: 3x –4y + 15 = 0 Exercise 2: Find the equation of the circle (C) passing through three points A( -2; 4); B(5; 5); C(6; -2). Exercise 3: Given the circle (C): 2 2 2 2 2 0x y x y+ - - - = and the line (d): x + 2y –1 = 0. Find the points of intersection of the line and the circle. PHỤC LỤC 3 ( Sử dụng padlet hoặc azota ) Test P1.(4 point) Given a line D with equation ( )2 3 4 5 x t t R y t = +ì Îí = - +î and a point ( )3;6M - . a) Find the coordinates of a point on D and a direction vector of D . b) Find the parametric equation of the line d passing through M and being parallel to D . P2. (2 point) Find the equation of the circle (C) centered at ( )5,1I and passing through the point ( )2,5M . P3. (4 point) Which of the following equations are the equations of the circles? Find the centers and the radius if they are. ( )2 2 2 4 4 0 1x y x y+ - - - = ( )2 2 6 2 20 0 2x y x y+ - + + = Answer P1a) Let 0t = , we have the coordinates of a point ( )0 2, 4M - on D . (1 p) A direction vector of D is: ( )3,5a = r (1 p) b) The parametric equation of the line d passing through M and being parallel to D is 3 3 6 5 x t y t = - +ì í = +î (2 p) P2. We have ( ) ( )2 22 5 5 1 9 16 25 5R IM= = - + - = + = = (1p) The equation of the circle (C): ( ) ( )2 25 1 25x y- + - = (1 p) P3a) ( )2 2 2 4 4 0 1x y x y+ - - - = We have: 1, 2, 4a b c= = = - 2 2 1 4 4 9 0a b c+ - = + + = > Hence, (1) is the equation of the circle with center ( )1,2I (1 p) and the radius 3R = (1 p) b) ( )2 2 6 2 20 0 2x y x y+ - + + = We have: 3, 1, 20a b c= = - = 2 2 9 1 20 10 0a b c+ - = + - = - < (1 p) Hence, (2) is not the equation of a circle. (1 p)
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