If the equation x4−4x3+ax2+bx+1=0 has four roots. All of them are positive real roots then value of a and b are given.
a = 6, b = - 4
We know, sum of the roots
α+β+γ+δ=(−B)A=4
Since all the roots are positive.
Sum of the roots taking 2 at a time should also be positive.
Sum of the roots taking 2 at a time = a
So, a should be positive
a> 0
Sum of the roots taking 3 at a time = - b (it should also be positive)
So, b must be less than zero
b < 0
From the above given options only Option C satisfy the condition.