The values of k for which the quadratic equation 16x2 + 4kx + 9 = o has real and equal roots are
To have real and equal roots d = 0
b2 – 4ac = 0
here a = 16, b = 4k and c = 9
(4k)2 – 4 x 16 x 9 = 0
16 k2 – 576 = 0
k2 = 576 /16
k = 24/ 4
k = 6