Q.

Which of the following is always true

1 One root of the equation ax2+bx+c=0, in the form of p+q, then other root is p-q (p∈z, q∈z+)  
2 If the equation ax2+bx+c=0 is satisfied by more than two distinct numbers (real or complex), then it becomes an identity.  
3 If a=2 and b,c are integers and the roots of the quadratic equation ax2+bx+c=0 are rational, then the roots must be integers.  
4 a,b,c are in A.P and G.P then (a,b,c) can be (k,k,k) for all k∈R  

Ans.

(2)

a, b can be irrational