atar90plus
01000101=YES! YES! YES!
- Joined
- Jan 16, 2012
- Messages
- 628
- Gender
- Male
- HSC
- 2013
Could you guys please help me with these questions. I am pretty bad with parametrics at the moment (trying to review) with only getting just above half of the total parametrics questions correct in my prelim. I done most of them already but just got stuck in parts of the question
4. Find the equation of the tangent to the parabloa x^2=-2y which is parallel to the line 2x+3y-5=0 and also find the point of contact between this line and the parabola. Answer: y=-2/3x +2/9, (2/3, -2/9)
For the first part of the question (equation of tangent) I got y=-2/3x +10/3 so I am not sure if my expansion/calculations are off or if the answer is wrong. I do not know how to find the POC though
6. P(2ap,ap^2) and Q(2aq,aq^2) are two points on the parabola x^2=4ay
c) If S is the focus of the parabola, prove that : 1/SP +1/SQ =1/a
7. Two points P(2AP,Ap^2) and Q(2Aq,Aq^2) lie on the parabola x^2=4Ay, where A<0. The chord PQ passes through the focus.
c) Show that the chord PQ has length A(p+1/p)^2
4. Find the equation of the tangent to the parabloa x^2=-2y which is parallel to the line 2x+3y-5=0 and also find the point of contact between this line and the parabola. Answer: y=-2/3x +2/9, (2/3, -2/9)
For the first part of the question (equation of tangent) I got y=-2/3x +10/3 so I am not sure if my expansion/calculations are off or if the answer is wrong. I do not know how to find the POC though
6. P(2ap,ap^2) and Q(2aq,aq^2) are two points on the parabola x^2=4ay
c) If S is the focus of the parabola, prove that : 1/SP +1/SQ =1/a
7. Two points P(2AP,Ap^2) and Q(2Aq,Aq^2) lie on the parabola x^2=4Ay, where A<0. The chord PQ passes through the focus.
c) Show that the chord PQ has length A(p+1/p)^2
