circles help(hardcore question)

https://gyazo.com/d1ae66a4fcc1e24e442511c7a06597d7
please help
i got up to finding the distances but am just confused on what to do right after

(edited 3 years ago)

Scroll to see replies

Reply 1

mqb2766

Original post by HelloZello

https://gyazo.com/d1ae66a4fcc1e24e442511c7a06597d7
please help

Have you sketched it?

Reply 2

HelloZello

yeah I just drew a diagram with a tangent intersecting at A and another tangent intersecting at B- I found the radius to be root 20 and CP(centre to point P(x,y) in the question said it was root 65 so I was thinking of doing pythagoras and I got AP=root 45 and next I was thinking of finding P through using the distance formula between 2 points A and P which I already know of A and using the Length of AP I got root 45=(root (6-x) squared+(-1-y)squared)-all varables are in the roots and I was thinking of finding the gradient of Ac and using the perpendicular gradient to find the equation of line intersecting at A and making y the subject and substituting in that formula I got and I'm kinda confused on what to do next since there seems to be so much working out

Reply 3

HelloZello

https://gyazo.com/9606f02d4992d072d8e153f6b133f9f0

Reply 4

HelloZello

wait I think I found my mistake hold up I didn't read the question tangents at A AND b intersect at P yikes i just followed my teachers working out

Reply 5

mqb2766

Original post by HelloZello

https://gyazo.com/9606f02d4992d072d8e153f6b133f9f0

That's the question again?
A bit of simple trig should see you good with the right diagram.

Reply 6

HelloZello

yeah-oh I never considered using trig for some reason so that seems to be making the question harder hmmmmmmm

Reply 7

mqb2766

Original post by HelloZello

yeah-oh I never considered using trig for some reason so that seems to be making the question harder hmmmmmmm

Can you upload what you've done / tried. For trig, read congruent triangles.

Reply 8

HelloZello

i dont have a phone at the moment srry only a pc but if I do get a solution ill try to type it here...

Reply 9

mqb2766

Original post by HelloZello

i dont have a phone at the moment srry only a pc but if I do get a solution ill try to type it here...

Sure, you get the equation of the circle. And for each {P,B} pair, you have two congruent right angled triangles PAC and PBC where C is the centre. That's about it, shouldn't need too much work.

(edited 3 years ago)

Reply 10

HelloZello

Original post by mqb2766

Sure, you get the equation of the circle. And for each {P,B} pair, you have two congruent right angled triangles PAC and PBC where C is the centre. That's about it, shouldn't need too much work.

still not sure

nevermind

Original post by HelloZello

still not sure

It really would help to see a sketch of what you think the problem looks like and what you've done. You can treat it as a line intersection, ... problem, but a bit of geometry will get you there quicker.

Reply 13

HelloZello

https://gyazo.com/7e56110aab2a0cb3cf64a4054f5065dc thats the answers its just substitution after substitution it'll make you go crazy

Reply 14

mqb2766

Original post by HelloZello

https://gyazo.com/7e56110aab2a0cb3cf64a4054f5065dc thats the answers its just substitution after substitution it'll make you go crazy

I agree. The diagram is the most important part - the two congruent right angled triangle with lengths.
What are you asking about, given that you have the "solution"

(edited 3 years ago)

Reply 15

HelloZello

ah no i didnt solve it- that was the answers on that question i tried to solve it without looking at the questions lol

Original post by mqb2766

I agree. The diagram is the most important part - the two congruent right angled triangle with lengths.
What are you asking about, given that you have the "solution"

Reply 16

mqb2766

Original post by HelloZello

ah no i didnt solve it- that was the answers on that question i tried to solve it without looking at the questions lol

If you have a question about what you've done, just upload it. Otherwise, if it's about the solution, what don't you understand?

Reply 17

HelloZello

-i cant upload if I don't have a phone so yh wish I did
-I think I might be confusing myself with the congruency portion of the question I tried to find the arguments and maybe use the sine rule(a/sinA=b/sinB) for finding out the length I think am overcomplicating this question,srry for being a burden