Q11Written answer
Find the sine of the angle between the vectors 
and 
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Worked solution
Thus, sin θ = 2/√7
NCERT Exemplar · Class 12 · Maths
Chapter 10: Vector Algebra
Practice each question, then open the answer or worked solution.
Exercise 10.3
Textbook page 215 · 14 questionsQ12Written answer
If A, B, C, D are the points with position vectors 
respectively, find the projection of 
along
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Worked solution
We have,
Q13Written answer
Using vectors, find the area of the triangle ABC with
vertices A(1, 2, 3), B(2, – 1, 4) and C(4, 5, – 1).
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Worked solution
Given vertices A(1, 2, 3), B(2, – 1, 4) and C(4, 5, – 1).
Q14Written answer
Using vectors, prove that the parallelogram on the same base and between the same parallels are equal in area.
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Worked solution
Let’s consider ABCD and ABFE be two parallelograms on the same base AB and between same parallel lines AB and DF.
– Hence proved.