4u conics questions! (1 Viewer)

[gh0stface]

Hi guys, im having stuck on a few conics questions from the terrylee book. The answers dont explain it properly, or atleast it doesnt make sense to me.


1. The normal at an end P(x1,y1) of the latus rectum of the ellipse (x^2)/(a^2)+(y^2)/(b^2) = 1 meets the y-axis in M, and Pn is the abscissa (<-----wtf does this mean) of P (ie PN is perpendicular to the y-axis). Prove that MN = A.




2. M and N are the respective feet of the perpendiculars from the foci, S S', onto a variable tangent to the ellipse (x^2)/(a^2)+(y^2)/(b^2) = 1.

Prove that SM. S'N = b^2

( this question u can use the tangent at point P(acosx, bsinx) or the general tangent y=mx(+-)Sqrt( a^2.m^2+b^2) )


Anyhelp is greatly appreciated.


thanks.

 

[YannY]

Hi guys, im having stuck on a few conics questions from the terrylee book. The answers dont explain it properly, or atleast it doesnt make sense to me.


1. The normal at an end P(x1,y1) of the latus rectum of the ellipse (x^2)/(a^2)+(y^2)/(b^2) = 1 meets the y-axis in M, and Pn is the abscissa (<-----wtf does this mean) of P (ie PN is perpendicular to the y-axis). Prove that MN = A.




2. M and N are the respective feet of the perpendiculars from the foci, S S', onto a variable tangent to the ellipse (x^2)/(a^2)+(y^2)/(b^2) = 1.

Prove that SM. S'N = b^2

( this question u can use the tangent at point P(acosx, bsinx) or the general tangent y=mx(+-)Sqrt( a^2.m^2+b^2) )


Anyhelp is greatly appreciated.


thanks.

Abscissa means the x coordinate.

 

[YannY]

does your terry lee book have no solutions?