hello : (3x²+kx-1) is a quadratic polynome when : a =3 , b=k , c= -1 the discriminat Δ = b²-4ac ≥ 0 because ac = -3 < 0 -4ac >0 and b²≥0 the quadratic polynome has :2 solutios or 1 solution (Change of sign) conclusion : is never always positive for any value of k
