# CONIC SECTION PDF

Sections of a cone Let lbe a fixed vertical line and m be another Thus, conic sections are the curves obtained by intersecting a right. CONIC SECTIONS Fig 2. Fig 3 cone and extending indefinitely far in both directions (Fig). The point V is called the vertex; the line l is the axis of. REVIEW OF CONIC SECTIONS. In this section we give geometric definitions of parabolas, ellipses, and hyperbolas and derive their standard equations.

In this unit we study the conic sections. These are the curves obtained when a cone is cut by a plane. We find the equations of one of these curves, the parabola . Formulas. • Lessons through Write and graph equations of parabolas, circles, ellipses, and hyperbolas. • Lesson Identify conic sections. • Lesson 8- 7. Recognize the four basic conics: circles, parabolas, ellipses, and hyperbolas. A conic section (or simply conic) can be described as the intersection of a plane.

Find a 7 by solving for the length of the transverse axis, 2a, which is the distance between the given vertices. Determine the orientation of the transverse axis by comparing the equation to the standard forms for vertical and horizontal hyperbolas.

## Conic Sections: Treated Geometrically by W. H. Besant

Determine the coordinates of the vertices and co-vertices a. Sketch the central rectangle and extend the diagonals to show the asymptotes.

Draw two smooth curves to form the hyperbola. The axis of symmetry passes through the focus and vertex and is perpendicular to the directrix.

The vertex is the midpoint between the directrix and the focus. The line segment that passes through the focus and is parallel to the directrix is called the latus rectum, also called the focal diameter.

## Treatise on conic sections

Set 4p equal to the coefficient of the first-degree polynomial term to solve for the coordinates of the focus, at p, 0 for horizontal parabolas or at 0, p for vertical parabolas.

Draw a smooth curve that passes through both endpoints and the vertex at the origin.

This translation results in the standard form of the equation with x replaced by x h and y replaced by y k. From the standard form equation of an ellipse, how can you tell if the major axis is a vertical line or a horizontal line? What is the transverse axis of a hyperbola?

From the standard form equation of a hyperbola, how do you find the line equations for the asymptotes? What is the focal diameter? State the coordinates of their vertices, foci and equations of the directrixs.

## You are here

Sketch their graphs. In a suspension bridge the shape of the suspension cable is parabolic.

The distance between the 2 towers are m and the lowest point of the suspension cable is 30 m below the mid point of the line joining the highest point of the 2 towers. Find the height of the cable at 15 m and 30 m from the middle of the road.

A bridge is to be built in the shape of a parabolic arch. The bridge has a span of m and a maximum height of 25 m. Find the height of the arch at distance 10 m from the center.

A parabolic is formed by revolving a parabola about its axis. Here we reconcile the two definitions of ellipses by locating the second focus of a Keplerian orbit.

Theorem Into the conical cup, inscribe a paraboloid of revolution so that it touches the secting plane. Then the projection of the point of tangency to the horizontal plane is the second focus of the projected conic section the vertex of the cone being the first one.

Proof First, note that a paraboloid of revolution is the locus of points equidistant from its focus lying on the axis of revolution and the directrix plane perpendicular to it. Consequently, the plane tangent to the paraboloid at a given point is the locus of points equidistant from the focus and the foot of the perpendicular dropped from the given point to the directrix. This shows that the direction normal to the tangent plane makes equal angles with the direction to the focus and the direction of the axis, which implies the famous optical property of the parabolic mirror to reflect all rays parallel to the axis into the focus.