TERM: 2ND TERM
WEEK 7
Class: Senior Secondary School 2
Age: 16 years
Duration: 40 minutes of 4 periods
Subject: Further Mathematics
Topic: Vectors in Two Dimensions III – Scalar (Dot) Product and Its Application
Focus: Understanding the scalar (dot) product, its formula, and its geometric and trigonometric applications.
SPECIFIC OBJECTIVES:
By the end of the lesson, students should be able to:
- Define the scalar (dot) product of two vectors.
- Apply the scalar product in geometry and trigonometry.
- Solve problems involving the scalar product in practical situations.
INSTRUCTIONAL TECHNIQUES:
• Lecture and Explanation
• Guided Demonstration
• Application of formulas through practical examples
• Question and Answer
• Problem-solving exercises
INSTRUCTIONAL MATERIALS:
• Whiteboard and markers
• Charts illustrating geometrical applications of the scalar product
• Vectors’ diagrams showing angles between vectors
• Calculators (optional)
PERIOD 1 & 2: Introduction to Scalar (Dot) Product
PRESENTATION:


EVALUATION (5 Exercises):
- Given vectors A=(2,3) and B=(4,−1) calculate A⋅B
- What is the scalar product of two perpendicular vectors?
- If A=(5,2) and B=(3,6) find the angle between them.
- Explain the significance of the scalar product being zero.
- Find the scalar product of vectors A=(3,4) and B=(2,1)
CLASSWORK (5 Questions):
- Calculate the scalar product of A=(6,7) and B=(3,4)
- Given vectors A=(8,−4) and B=(5,3) determine the angle between them.
- Find the scalar product of vectors A=(2,5) and B=(6,3)
- How does the scalar product change when the two vectors are perpendicular?
- Explain why the scalar product can be used to find the angle between vectors.
ASSIGNMENT (5 Tasks):
- Derive the formula for the scalar product using the angle between two vectors.
- Solve a problem where the scalar product of two vectors is used to find the projection of one vector onto another.
- Using vectors A=(1,2) and B=(4,−3) find the angle between the vectors.
- Explain the real-life applications of the scalar product in geometry and physics.
- Find the scalar product of two vectors in 3D space.
PERIOD 3 & 4: Application of Scalar (Dot) Product in Geometry and Trigonometry
PRESENTATION:
Step
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Teacher’s Activity
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Student’s Activity
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Step 1 – Problem Introduction
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Provides problems related to the application of the scalar product in geometry, e.g., finding the projection of one vector onto another or the angle between vectors in a triangle.
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Students attempt the problems, asking for clarification if needed.
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5. Solve a problem using the scalar product to calculate the angle between two vectors in 3D space.
CLASSWORK (5 Questions):
- Using vectors A=(6,7) and B=(2,5) find the projection of
- Solve for the angle between A=(5,6) and B=(7,−3)
- Given vectors A=(4,1) and B=(3,−2) calculate the area of the parallelogram they form.
- Find the scalar product of vectors A=(2,5) and B=(4,3)
- Derive the formula for the projection of one vector onto another.
ASSIGNMENT (5 Tasks):
- Solve for the projection of vector A=(3,1) on B=(5,2)).
- Find the angle between vectors A=(8,−2) and B=(7,4)
- Use the scalar product to calculate the area of a triangle given vectors A=(2,3) and B=(4,5)
- Discuss the role of scalar product in finding distances between points in space.
- Solve a real-life problem involving the use of the scalar product, such as calculating the angle between two vectors in a physics context.