Q)
(chatquestion)...39 x2-2x+ y = 0, P(-3,-15)
40 The two towers of a suspension bridge are 300 meters apart
and extend 80 meters above the road surface. If the cable (in
the shape of a parabola) is tangent to the road at the center
of the bridge, find the height of the cable above the road at
50 meters and also at 100 meters from the center of the
bridge. (Assume that the road is horizontal.) See Fig. 15.
the
80 meters
s in
FIGURE 15
41 At a point P on a parabola a tangent line is drawn. This line
intersects the axis of the parabola at a point A. If F denotes
the focus, show that AAPF is isosceles.
42 Let P(x1, yı) be a point (not the vertex) on the parabola
y? = 2px. Find the equation of the line normal to the
parabola at this point. Show that this normal line intersects
the x axis at the point Q(x, + p, 0).
AND THE ELLIPSE*
points (x, y) which are at a given distance r from a fixed point
sa circle. We also use the statement, the graph of
m the formula for the distance between two points we know
such points
r=/(x- h)² +(y– k)²,
cerial on the circle and the ellipse as well as another problem set, may
pendix 2, Sections 1 and 3, at the end of the book.
ETRY IN THE PLANE
ring...(No. 41)
...
