128) Sum of roots, @ + & =
129) Product of roots, @& = <o:p></o:p>
130) Parabola (x-h)2 = 4a(y-k) has<o:p></o:p>
(i) focus at (ii) directrix equation (iii) vertex at (iv) axis parallel to<o:p></o:p>
131) As above but for (y-k)2 = 4a(x-h)<o:p></o:p>
132) Common difference, T2 - __ = __ -...