If `0 <= x < 2pi`, then the number of real values of x, which satisfy the equation `cos x + cos 2x + cos 3x + cos 4x = 0`;

If A = [{:( 0,0,0),(0,0,0) ,(0,1,0):}] ,then A is

If A = [{:( 0,0,0),( 1,0,0),(0,1,0):}] ,then

If A = [(3,0,0),(0,3,0),(0,0,3)] , then |A||adj A| =...

If A = {:[(2,0,0),(0,2,0),(0,0,2)]:}, then A^(6) = .........

If A =[{:(2,0,0),(0,1,0),(0,0,1):}] then adj(A) =

If A =[{:(a,0,0),(0,a,0),(0,0,a):}] , then det (adjA) equals

If x, y, z are non-zero real numbers, then the inverse of matrix A=[(x,0, 0) ,(0,y,0),( 0, 0,z)] is (A) [[x^(-1),0,0],[0,y^(-1),0],[0,0,z^(-1)]] (B) xyz[[x^(-1),0,0],[0,y^(-1),0],[0,0,z^(-1)]] (C) (1)/(xyz)[[x,0,0],[0,y,0],[0,0,z]]] (D) (1)/(xyz)[[1,0,0],[0,1,0],[0,0,1]]

If x ,\ y ,\ z are non-zero real numbers, then the inverse of the matrix A=[x0 0 0y0 0 0z] , is [x^(-1)0 0 0y^(-1)0 0 0z^(-1)] (b) x y z[x^(-1)0 0 0y^(-1)0 0 0z^(-1)] (c) 1/(x y z)[x0 0 0y0 0 0z] (d) 1/(x y z)[1 0 0 0 1 0 0 0 1]

Choose the correct answer in questions 17 to 19: If x, y, z are nonzero real numbers then the inverse of metrix A=[{:(x,0,0),(0,y,0),(0,0,z):}] is : (a) [{:(x^(-1),0,0),(0,y^(1),0),(0,0,z^(1)):}] (b) xyz[{:(x^(-1),0,0),(0,y^(1),0),(0,0,z^(1)):}] ( c) 1/(xyz)[{:(x,0,0),(0,y,0),(0,0,z):}] (d) 1/(xyz)[{:(1,0,0),(0,1,0),(0,0,1):}]