Let Tn denote the number of triangles which can equal to be formed by using the vertices of a regular polygon of n sides. If Tn + 1 - Tn = 28, then n equals
4
5
6
8
A plane makes intercepts a, b, cat A, B, C on the coordinate axes respectively. If the centroid of the ABC is at (3, 2, 1), then the equation of the plane is
x + 2y + 3z = 9
2x - 3y - 6z = 18
2x + 3y + 6z = 18
2x + y + 6z = 18
The equation of the line passing through the point (3, 0,- 4) and perpendicular to the plane 2x - 3y + 5z - 7 = 0 is
Equation of the plane passing through t intersection of the planes x + y + z = 6 and 2x + 3y + 4z + 5 = 0 and the point (1, 1, 1)
20x + 23y + 26z - 69 = 0
31x + 45y + 49z + 52 = 0
8x + 5y + 2z - 69 = 0
4x + 5y + 6z - 7 = 0
The equation of the plane containing the line = = and = = is
8x - y + 5z - 8 = 0
8x + y - 5z - 7 = 0
x - 8y + 3z + 6 = 0
8x + y - 5z + 7 = 0