If the two roots `(a-1)(x^4+x^2+1)+(a+1)(x^2+x+1)^2`=0 are real and distinct, then the set of all values of 'a' is........

If all roots of the equation x^(3)+ax^(2)-ax-1=0 are real and distinct,then the set of values of a is

If the roots of 5x^(2)-kx+1=0 are real and distinct then

(B) (2, 9/4) If two roots of the equation (a-1) (x^2 + x + 1 )^2-(a + 1) (x^4 + x^2 + 1) = 0 are real and distinct, then a lies in the interval

(B) (2, 9/4) If two roots of the equation (a-1) (x^2 + x + 1 )^2-(a + 1) (x^4 + x^2 + 1) = 0 are real and distinct, then a lies in the interval

(B) (2,9/4 ) If two roots of the equation (a-1)(x^(2)+x+1)^(2)-(a+1)(x^(4)+x^(2)+1)=0 are real and distinct,then a lies in the interval

Show that the equation x^2+a x-4=0 has real and distinct roots for all real values of a .

If the equation (x/(1+x^2))^2+a(x/(1+x^2))+3=0 has exactly two real roots which are distinct, then the set of possible real values of a is ((-13)/2,0) (b) (oo,-(13)/2) ((-13)/2,(13)/2) (d) ((13)/2,oo)