If `D_(1)` and `D_(2)` are two `3xx3` diagonal matrices, then which of the following is/are true ?

If A, B and C are invertible matrices of some order, then which one of the following is not true?

Which of the following microscope produce 3D-image?

For an increasing A.P. a_1, a_2,..... a_n ifa_1+a_3+a_5=-12 and a_1a_3a_5=80 , then which of the following is/are true? a. a_1=-10 b. a_2=-1 c. a_3=-4 d. a_5=+2

Let Xa n dY be two arbitrary, 3xx3 , non-zero, skew-symmetric matrices and Z be an arbitrary 3xx3 , non-zero, symmetric matrix. Then which of the following matrices is (are) skew symmetric? a. Y^3Z^4 Z^4Y^3 b. x^(44)+Y^(44) c. X^4Z^3-Z^3X^4 d. X^(23)+Y^(23)

If the equation of the ellipse is 3x^2+2y^2+6x-8y+5=0 , then which of the following is/are true? (a) e=1/(sqrt(3)) (b)Center is (-1,2)dot (c)Foci are (-1,1)a n d(-1,3)dot (d)Directrices are y=2+-sqrt(3)

Let S(k)=1+3+5+...+(2k-1)=3+k^(2) . Then which of the following is true?

Two sides of a rhombus are along the lines, x-y+1=0 and 7x-y-5=0 . If its diagonals intersect at (-1,-2) , then which one of the following is a vertex of this rhombus ? (1) (-3,-9) (2) (-3,-8) (3) (1/3,-8/3) (4) (-(10)/3,-7/3)