The Student Room Group
Uni students - Complete our survey >>
Uni students - Complete our survey >>
Uni students - Complete our survey >>

Circle Geometry Question

I had this question in an assessment today and I couldn't do part (c) - it was a non calculator paper as well. I would appreciate if anyone could show me how to do it! :smile:

The circle C has centre A(2,1) and passes through the point B(10,7)



1.

Find an equation for C.




The line l1is tangent to C at the point B.


b) Find an equation for l1 .


The line L2 is parallel to l1and passes through the midpoint of AB.


Given that L2 intersects C at the points P and Q,


c) Find the length of PQ, in simplified surd form.
Define M to be the midpoint of AB. (So L2 goes through M).
Find the distances AP and AM, then you can find PM using Pythagoros. And of course PM = MQ, so ...

(Note: drawing a diagram is going to help, too).
Reply 2
Avatar for GingerGnu
GingerGnu
OP
1
Original post by DFranklin
Define M to be the midpoint of AB. (So L2 goes through M).
Find the distances AP and AM, then you can find PM using Pythagoros. And of course PM = MQ, so ...

(Note: drawing a diagram is going to help, too).


Sorry if I'm just being dumb, but how can you find the length of AP if you don't have the coordinates of P?
A is the center of the circle, P is a point on the circle.
Reply 4
Avatar for GingerGnu
GingerGnu
OP
1
Original post by DFranklin
A is the center of the circle, P is a point on the circle.


Oh I feel stupid now!! Sorry :P But thank you very much :smile:

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you