Given:
The vertices of a triangle are A (1, 2, 3), B (0, 4, 1), C (-1, -1, -3)
By using the distance formula,
So, AB/AC = 3/7
AB: AC = 3:7
BD: DC = 3:7
Then, m = 3 and n = 7
B(0, 4, 1) and C(-1, -1, -3)
Coordinates of D by using section formula is given as
∴ The coordinates of D are (-3/10, 5/2, -1/5).