A level math helppppppppp

OP

Original post by Qxi.xli

you know the centre and you know one other point on the circle (where it crosses the x-axis). So find the distance between them.

I don't know the x value for that point

Reply 7

username3477548

20

Original post by badoom1234

I don't know the x value for that point

its going to be 9. It's right above the centre. This is why another user recommended drawing a labelled diagram- it helps a lot.

(edited 2 years ago)

Reply 8

OP

Original post by hhqurashi

a radius can't be 0 lol, centre (9,-6) basically means 9 to the right 6 down from the origin. Therefore since the point (9,0) is on the circle and the centre is (9,-6) the radius is...

wow okay now that makes a lott of sense, thank you for supporting me at my dumbest moment

Reply 9

username3890670

11

Original post by badoom1234

wow okay now that makes a lott of sense, thank you for supporting me at my dumbest moment

np lol, we all miss the bigger picture sometimes

Reply 10

OP

Original post by hhqurashi

np lol, we all miss the bigger picture sometimes

everytime i look at that question it just seems more and more obvious damn :frown:

. I'm ashamed to say it but i'm stuck on part b too

Reply 11

Original post by badoom1234

everytime i look at that question it just seems more and more obvious damn :frown:

. I'm ashamed to say it but i'm stuck on part b too

Have you sketched the solutions? It really does help.

Reply 12

OP

Original post by mqb2766

Have you sketched the solutions? It really does help.

i've put a line cutting the circle at two points P and Q but I don't understand how I can use the given distance to calculate the points. Also, the line of drawn ive given the equation y=c because it's parallel to the x-axis. I'm thinking that you need to sub the y=c into the equation of the circle and the use the discriminant to maybe find the c value by getting rid of the x's but then i'm not using the given distance so I don't thikn that method would work

Reply 13

Original post by badoom1234

i've put a line cutting the circle at two points P and Q but I don't understand how I can use the given distance to calculate the points. Also, the line of drawn ive given the equation y=c because it's parallel to the x-axis. I'm thinking that you need to sub the y=c into the equation of the circle and the use the discriminant to maybe find the c value by getting rid of the x's but then i'm not using the given distance so I don't thikn that method would work

Can you upload your sketch? You should have two lines as there are two solutions, and make sure you mark on relevant radii, as per the previous part.

(edited 2 years ago)

Reply 14

OP

Original post by Qxi.xli

its going to be 9. It's right above the centre. This is why another user recommended drawing a labelled diagram- it helps a lot.

Yeah thank you! I drew a diagram but i jjust didn't think about that

Reply 15

OP

Original post by mqb2766

Can you upload your sketch? You should have two lines as there are two solutions, and make sure you mark on relevant radii, as per the previuos part.

why would i have two lines excluding the radii?

Reply 16

Original post by badoom1234

why would i have two lines excluding the radii?

Id be happy to see a sketch with one line on.
Its easier to explain - see what youre tihinking.

(edited 2 years ago)

Reply 17

OP

WIN_20210129_11_00_45_Pro.jpg52.8KB

Original post by mqb2766

Id be happy to see a sketch with one line on.
Its easier to explain - see what youre tihinking.

(edited 2 years ago)

Reply 18