The roots of the equation `12 x^2 + x - 1 = 0` is :

Answer

a

Explanation

Let `(x)=x^(4)-4x^(3)+12x^(2)+x-1`
`:.f'(x)=4x^(3)-12x^(2)+24x+1`
`impliesf''(x)=12x^(2)-24x+24`
`=12(x^(2)-2x+2)`
`=12[(x-1)^(2)+1]gt0`
i.e. `f"(x)` has no real roots.
Hence `f(x)` has maximum two distinct real roots, where `f(0)=-1`.