There is two possible conic section that can be formed when the plane intersects the vertical axis, a circle, and an ellipse. Cutting one nappe of double napped cone perpendicular to the vertical axis means the cut is straight across the cone making a right angle. The conic section formed would be a circle.
-230 because it is farther away from 0
It has become somewhat fashionable to have students derive the Quadratic Formula themselves; this is done by completing the square for the generic quadratic equation ax2 + bx + c = 0. While I can understand the impulse (showing students how the Formula was invented, and thereby providing a concrete example of the usefulness of abstract symbolic manipulation), the computations involved are often a bit beyond the average student at this point.
Ooo! I love these! Ok so your IQR is C or D. I might have my calculations wrong if so. Sorry!
