94.If A (2, – 1, 3), B (8, 5, – 6) and C (4, 1, 0) are the vertices of a triangle. show that (i) AB = 3 AC (ii) The direction-cosines of  areÂ
Let O be the origin. A is (2, -1, 3) Â Â Â Â Â Â Â Â Â Â Â Â B is (8, 5, -6) Â Â Â Â Â Â Â Â Â Â Â Â C is (4, 1, 0) Â Â Â Â Â Â Â Â Â Â Â Â Â Â
(i) Â Â Â Â
(ii)                    direction cosines of  i.e.,  coeffs. of  areÂ
74 Views
Advertisement
Advertisement
Short Answer Type
95.Show that vector  is equally inclined to the axes OX. OY and OZ.Â
77 Views
Long Answer Type
96.Show that the points A (6. – 7, 0) B (16, – 19, – 4). C (0, 3, – 6), D (2, – 5, 10) are such that AB and CD intersect at the point P (1, – 1, 2).
77 Views
97.The vectors of magnitude a, 2a, 3a meet at a point and their directions arc. along the diagonals of three adjacent faces of a cube. Determine the magnitude of their resultant.
263 Views
Short Answer Type
98.Write all the unit vectors in XY-plane.
149 Views
Advertisement
99.Write down a unit vector in XY-plane, making an angle of 30° with the positive direction of x-axis.
91 Views
Long Answer Type
100.A girl walks 4 km towards west, then she walks 3 km in a direction 30° east of north and stops. Determine the girl’s displacement from her initial point of departure.