The angel between the two diagonals of a cube is a. `30^0` b. `45^0` c. `cos^(-1)(1/(sqrt(3)))` d. `cos^-(1/3)`

Show that the angle between two diagonals of a cube is cos^(-1)(1/3)dot

Show that the angle between two diagonals of a cube is cos^(-1)sqrt(1/3)dot

If veca=(3,1) and vecb=(1,2) represent the sides of a parallelogram then the angle theta between the diagonals of the paralelogram is given by (A) theta=cos^-1(1/sqrt(5)) (B) theta=cos^-1(2/sqrt(5)) (C) theta=cos^-1 (1/(2sqrt(5))) (D) theta = pi/2

In a quadrilateral A B C D , vec A C is the bisector of vec A Ba n d vec A D , angle between vec A Ba n d vec A D is 2pi//3 , 15| vec A C|=3| vec A B|=5| vec A D|dot Then the angle between vec B Aa n d vec C D is cos^(-1)(sqrt(14))/(7sqrt(2)) b. cos^(-1)(sqrt(21))/(7sqrt(3)) c. cos^(-1)2/(sqrt(7)) d. cos^(-1)(2sqrt(7))/(14)

If vec aa n d vec b are any two vectors of magnitudes 1 and 2, respectively, and (1-3 vec adot vec b)^2+|2 vec a+ vec b+3( vec axx vec b)|^2=47 , then the angel between vec aa n d vec b is pi//3 b. pi-cos^(-1)(1//4) c. (2pi)/3 d. cos^(-1)(1//4)

A tetrahedron has vertices O(0,0,0),A(1,2,1),B(2,1,3),a n dC(-1,1,2), then angle between face O A Ba n dA B C will be a. cos^(-1)((17)/(31)) b. 30^0 c. 90^0 d. cos^(-1)((19)/(35))

The angle between two planes x+2y+2z=3 and -5x+3y+4z=9 is (A) cos^-1(3sqrt(2))/10 (B) cos^-1 (19sqrt(2))/30 (C) cos^-1 (9sqrt(2))/20 (D) cos^-1 (3sqrt(2))/5

The angle between i and line of the intersection of the plane vec r . ( hat i+2 hat j+3 hat k)=0 and vec r . (3 hat i+3 hat j+ hat k)=0 is a. cos^(-1)(1/3) b. cos^(-1)(1/(sqrt(3))) c. cos^(-1)(2/(sqrt(3))) d. none of these

The diection cosines of two lines are proportional to (2,3,-6) and (3,-4,5), then the acute angle between them is (A) cos^-1{49/36} (B) cos^-1 {(18sqrt(2))/35} (C) 96^0 (D) cos^-1(18/35)

If veca and vecb are two unit vectors such that veca+2vecb and 5veca-4vecb are perpendicular to each other then the angle between veca and vecb is (A) 45^0 (B) 60^0 (C) cos^-1(1/3) (D) cos^-1(2/7)