The position vectors of the points A, B, C and D are `hat(i)+hat(j)+hat(k), 2hat(i)+3hat(j), 3hat(i)+5hat(j)-2hat(k) " and " -hat(j)+hat(k)` respectively. Show that `vec(AB) " and " vec(CD)` are parallel and find the ratio of their moduli.

If the position vectors of the points A, B C are 3hat(i)-4hat(j)-4hat(k), 2hat(i)-hat(j)+hat(k) " and " hat(i)-3hat(j)-5hat(k) respectively. Show that ABC is right-angled triangle.

The position vectors of the points A, B and C are 2hat(i)+6hat(j)-hat(k), hat(i)+2hat(j)+4hat(k) " and " 3hat(i)+10hat(j)-6hat(k) respectively. Show that the points A, B and C are collinear.

If the position vectors of the points A, B, C are -2hat(i)+2hat(j)+2hat(k), 2hat(i)+3hat(j)+3hat(k) " and " -hat(i)-2hat(j)+3hat(k) respectively, show that ABC is an isosceles triangle.

The position vectors of the points A,B, and C are 2hat(i)+4hat(j)-hat(k), 4hat(i)+5hat(j)+hat(k) " and " 3hat(i)+6hat(j)-3hat(k) respectively. Show that the points form a right-angled triangle.

Let vec(a)=4hat(i)+3hat(j)-hat(k), vec(b)=5hat(i)+2hat(j)+2hat(k), vec(c)=2hat(i)-2hat(j)-3hat(k) " and "vec(d)=4hat(i)-4hat(j)+3hat(k), " prove that " vec(b)-vec(a) " and " vec(d)-vec(c) are parallel and find the ratio of their moduli.

The position vectors of the points A and B are 3hat(i)-hat(j)+7hat(k) " and " 4hat(i)-3hat(j)-hat(k) , find the magnitude and direction cosines of vec(AB)

If four points 2hat(i) + hat(j) + hat(k), hat(i) + hat(j) - hat(k), hat(j) - hat(k) and lamda hat(j) + hat(k) are coplanar then lamda =

(i) If the position vectors of the points A, B, C be 5hat(i)+3hat(j)+4hat(k), hat(i)+5hat(j)+hat(k) " and " -3hat(i)+7hat(j)-2hat(k) respectively, then show that the points B bisects the line-segment bar(AC) . (ii) The position vectors of the points P and Q are 5hat(i)-12hat(j)+5hat(k) " and " -4hat(i)+3hat(j)-hat(k) respectively. Find the position vectors of the trisection points of the line-segment bar(PQ) .

The position vectors of the point A ,B ,C and D are 3 hat i-2 hat j- hat k ,2 hat i+3 hat j-4 hat k ,- hat i+ hat j+2 hat k and 4 hat i+5 hat j+lambda hat k , respectively. If the points A ,B ,C and D lie on a plane, find the value of lambda .

The position vectors of three points are (a) -2hat(i)+3hat(j)+5hat(k), hat(i)+2hat(j)+3hat(k), 7hat(i)-hat(k) (b) hat(i)-2hat(j)+3hat(k), 2hat(i)+3hat(j)-4hat(k), -7hat(j)+10hat(k) In each case show that the three points are collinear.