Quadratic equation, roots, nature & problem solving.

Q1) For what values ofk does the quadratic equation 4x^2-12x-k=0 have no real roots? Q2) Find the values of k for which the quadratic equation 3x^2+kx+3=0 has real and equal roots? Q3) If one root of the equation 5x^2+13x +k =0 is the reciprocal of the other root then find the value of k.