If then

For such questions, we should know how to find the dot product and cross product. Dot product of two vectors is always a scalar quantity. The cross product of two vectors is a vector quantity.

If are non coplanar vectors then the roots of equation

The point of intersection of the plane will the stright line passing through the origin and perpendicular to the plane is

The position vector of the centre of the circle

The locus of midpoints of chords of  which subtend a right angle  at the centre is

𝐓𝐡𝐞𝐫𝐞 𝐚𝐫𝐞 𝐭𝐰𝐨 𝐔𝐫𝐧𝐬. 𝐔𝐫𝐧 𝐀 𝐡𝐚𝐬 𝟑 𝐝𝐢𝐬𝐭𝐢𝐧𝐜𝐭 𝐫𝐞𝐝 𝐛𝐚𝐥𝐥𝐬 𝐚𝐧𝐝 𝐮𝐫𝐧 𝐁 𝐡𝐚𝐬 𝟗 𝐝𝐢𝐬𝐭𝐢𝐧𝐜𝐭 𝐛𝐥𝐮𝐞 𝐛𝐚𝐥𝐥𝐬. 𝐅𝐫𝐨𝐦 𝐞𝐚𝐜𝐡 𝐮𝐫𝐧 𝐭𝐰𝐨 𝐛𝐚𝐥𝐥𝐬 𝐚𝐫𝐞 𝐭𝐚𝐤𝐞𝐧 𝐨𝐮𝐭 𝐚𝐭𝐫𝐚𝐧𝐝𝐨𝐦 𝐚𝐧𝐝 𝐭𝐡𝐞𝐧 𝐭𝐫𝐚𝐧𝐬𝐟𝐞𝐫𝐫𝐞𝐝 𝐭𝐨 𝐭𝐡𝐞 𝐨𝐭𝐡𝐞𝐫. 𝐓𝐡𝐞 𝐧𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐰𝐚𝐲𝐬 𝐢𝐧 𝐰𝐡𝐢𝐜𝐡 𝐭𝐡𝐢𝐬 𝐜𝐚𝐧 𝐛𝐞 𝐝𝐨𝐧𝐞 𝐢𝐬

𝐓𝐡𝐞 𝐧𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐩𝐞𝐫𝐦𝐮𝐭𝐚𝐭𝐢𝐨𝐧𝐬 𝐟𝐫𝐨𝐦 𝐭𝐡𝐞 𝐥𝐞𝐭𝐭𝐞𝐫𝐬 𝐀 𝐭𝐨 𝐆 𝐬𝐨 𝐭𝐡𝐚𝐭 𝐧𝐞𝐢𝐭𝐡𝐞𝐫 𝐭𝐡𝐞 𝐬𝐞𝐭 𝐁𝐄𝐆 𝐧𝐨𝐫 𝐭𝐡𝐞 𝐬𝐞𝐭 𝐂𝐀𝐃 𝐚𝐩𝐩𝐞𝐚𝐫𝐬 𝐢𝐬

A unit vector in the plane of is such that where is

If . Then altitude of the parallel piped formed by the vectors having base formed by is ( and , are reciprocal system of vectors)

The vector equals

is a tetrahedron in which is the origin and position vector of points A,B,C  are and respectively. A value of a for which shortest distance between and is

𝐓𝐡𝐞 𝐧𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐰𝐚𝐲𝐬 𝐢𝐧 𝐰𝐡𝐢𝐜𝐡 𝐭𝐡𝐞 𝐟𝐨𝐮𝐫 𝐟𝐚𝐜𝐞𝐬 𝐨𝐟 𝐚 𝐫𝐞𝐠𝐮𝐥𝐚𝐫 𝐭𝐞𝐭𝐫𝐚𝐡𝐞𝐝𝐫𝐨𝐧 𝐜𝐚𝐧 𝐛𝐞 𝐩𝐚𝐢𝐧𝐭𝐞𝐝 𝐰𝐢𝐭𝐡 𝐟𝐨𝐮𝐫 𝐝𝐢𝐟𝐟𝐞𝐫𝐞𝐧𝐭 𝐜𝐨𝐥𝐨𝐮𝐫𝐬 𝐢𝐬

T𝐡𝐞 𝐧𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐰𝐚𝐲𝐬 𝐢𝐧 𝐰𝐡𝐢𝐜𝐡 𝟓 𝐢𝐝𝐞𝐧𝐭𝐢𝐜𝐚𝐥 𝐛𝐚𝐥𝐥𝐬 𝐜𝐚𝐧 𝐛𝐞 𝐤𝐞𝐩𝐭 𝐢𝐧 𝟏𝟎 𝐢𝐝𝐞𝐧𝐭𝐢𝐜𝐚𝐥 𝐛𝐨𝐱𝐞𝐬, 𝐢𝐟 𝐧𝐨𝐭 𝐦𝐨𝐫𝐞 𝐭𝐡𝐚𝐧 𝐨𝐧𝐞 𝐜𝐚𝐧 𝐠𝐨 𝐢𝐧𝐭𝐨 𝐚 𝐛𝐨𝐱, 𝐢𝐬

𝐓𝐡𝐞 𝐧𝐮𝐦𝐛𝐞𝐫 𝐨𝐟 𝐰𝐚𝐲𝐬 𝐭𝐨 𝐟𝐢𝐥𝐥 𝐞𝐚𝐜𝐡 𝐨𝐟 𝐭𝐡𝐞 𝐟𝐨𝐮𝐫 𝐜𝐞𝐥𝐥𝐬 𝐨𝐟 𝐭𝐡𝐞 𝐭𝐚𝐛𝐥𝐞 𝐰𝐢𝐭𝐡 𝐚 𝐝𝐢𝐬𝐭𝐢𝐧𝐜𝐭 𝐧𝐚𝐭𝐮𝐫𝐚𝐥 𝐧𝐮𝐦𝐛𝐞𝐫𝐬 𝐬𝐮𝐜𝐡 𝐭𝐡𝐚𝐭 𝐭𝐡𝐞 𝐬𝐮𝐦 𝐨𝐟 𝐭𝐡𝐞 𝐧𝐮𝐦𝐛𝐞𝐫𝐬 𝐢𝐬 𝟏𝟎 𝐚𝐧𝐝 𝐭𝐡𝐞 𝐬𝐮𝐦𝐬 𝐨𝐟 𝐭𝐡𝐞 𝐧𝐮𝐦𝐛𝐞𝐫𝐬 𝐩𝐥𝐚𝐜𝐞𝐝 𝐝𝐢𝐚𝐠𝐨𝐧𝐚𝐥𝐥𝐲 𝐚𝐫𝐞 𝐞𝐪𝐮𝐚𝐥 𝐢𝐬