Q18 of 73 Page 440

In triangle ABC (Fig 10.18), which of the following is not true:

(a)

(b)

(c)

(d)

We know by triangle law of vectors,

…………..(1)

Therefore,

Hence (B) is true.

We know that

Putting in eq(1), we get

…….(2)

Hence (A) is also true.

Now,

Putting in eq(2)

Hence (D) is correct.

We are asked the option which is not true.

Therefore, the correct option is (C).

Find the position vector of the mid point of the vector joining the points P(2, 3, 4) and Q(4, 1, –2).

Show that the points A, B and C with position vectors, respectively form the vertices of a right angled triangle.

are two collinear vectors, then which of the following are incorrect:

(a)

(b)

(d) both the vectors have same direction, but different magnitudes.

Find the angle between two vectors with magnitudes √3 and 2 respectively having

In triangle ABC (Fig 10.18), which of the following is not true:(a) (b) (c) (d)