LAST LECTURE OVERVIEW Conic Section Informal def. Formal def. Eccentricity Vertex Directx Axis Directx Focus Method for Ellipse 2
DIRECTX FOCUS METHOD –FOR PARABOLA To construct a Parabola when the distance between focus from the directrix is equal to 60, by directrix focus method Method of drawing parabola by directrix focus method is same as explained before Only the position of the V is different, to fix the position of V, Divide OF into two equal parts. Mark V at the mid of the OF so that, � Then repeat all the procedure. 3
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PARABOLA–TANGENT AND NORAML To draw tangent and normal to the parabola at any point P on it. 10
Join point P with focus F. 11
Through F, draw a line perpendicular to PF to meet the directrix AB at T. 12
Join PT, which is tangent to the parabola at P. Tangent 13
Draw a line PN through P perpendicular to tangent PT, which is the required normal to the parabola at P. Normal Tangent 14
HOME WORK To construct a Hyperbola when the distance between focus from the directrix is equal to 60 and eccentricity =3/2, by directrix focus method To draw tangent and normal to the Hyperbola at any point P on it. 15