If a is matrix such that `A^(2)+A+2I=O`, then which of the following is/are true ?

Let theta in [ 0, pi/2] which one of the following is true ?

Which of the following is an orthogonal matrix ?

If A is a square matrix, then which of the following is not symmetric ?

It A is an invertible matrix, then which of the following is not true.

Which one o f the following statement is not true?

In DeltaABC, angleC=2angle A and AC=2BC. Then which of the following is/are True ?

IfI_1=int_0^1 2^(x^2) ,I_2=int_0^1 2^(x^3)dx ,I_3=int_1^2 2^(x^2)dx ,I_4=int_1^2 2^(x^3)dx , then which of the following is/are true? I_1> I_2 (b) I_2> I_1 I_3> I_4 (d) I_3 lt I_4

A=[{:(a,b),(b,-a):}] and MA=A^(2m) , m in N for some matrix M , then which one of the following is correct ?