4x^2 + px + 9 = 0
D = p^2 - 4*4*9 = 0
p^2 = 144
p = +/-12
4x+px+9=0
D=p^2-4*4*9=p^2-144
p^2-144=0
p^2=144
p=+-12
4x^2 + px + 9 = 0
D = p^2 - 4*4*9 = 0
p^2 = 144
p = +/-12
4x+px+9=0
D=p^2-4*4*9=p^2-144
p^2-144=0
p^2=144
p=+-12