4x^(2)+4bx-(a^(2)-b^(2))=0

If alpha,beta,gamma,delta are the roots of the equation x^(4)+Ax^(3)+Bx^(2)+Cx+D=0 such that alpha beta gamma delta =k and A,B,C,D are the roots of x^(4)-2x^(2)+4x^(2)+6x-21=0 such that A+B=0 then the value of (C)/(A), is

If alpha and beta are the roots of the equation x^(2)+ax+b=0 and alpha^(4) and beta^(4) are the roots of the equation x^(2)-px+q=0 then the roots of x^(2)-4bx+2b^(2)-p=0 are always

If lim_(xrarr1)(ax^(2)+bx+c)/((x-1)^(2))=2 then (a,b,c) is a) (2,-4,2) b) (2,4,2) c) (2,4,-2) d) (2,-4,-2)

The radius of the circle 3x^(2)+ by^(2) + 4bx - 6by + b^(2) = 0

IF the harmonic mean of the roots of sqrt(2) x^2-bx +(8-2sqrt(5))=0 is 4 then the value of b=