Conics (1 Viewer)

[goobi]

So the following is a Conics question from Terry Lee (p.111).



I'm just wondering whenever I attempt questions like 7(a) if I can just substitute the x and y values required into the equation given in order to get full marks, provided that we are told to 'prove' rather than 'derive' the equation of the chord.

Thanks in advance

 

[Carrotsticks]

Yeah that's fine, just sub in the parametric coordinates of the ellipse so if that satisfies it, then all points on the ellipse satisfy it.

Though personally I don't like taking formulas for granted and just subbing it in, I prefer deriving it.

Also, goobi pls.

 

[COLDBOY]

Yeah that's fine, just sub in the parametric coordinates of the ellipse so if that satisfies it, then all points on the ellipse satisfy it.

Though personally I don't like taking formulas for granted and just subbing it in, I prefer deriving it.

Also, goobi pls.

I hated those rules, just derive them

sin(a) + sin(b) = sin((a+b)/2 + (a-b)/2) + sin((b-a)/2 + (b+a)/2) im pretty sure thats what you need for that question, not this exactly but the principle.

like cos(a) - cos(b) = cos((a+b)/2 + (a-b)/2) - cos((b-a)/2 + (b+a)/2)

just expand that simplify it and you should get the equation. in terms of the terms they want