URGENT) C1 Coordinate Geometry Help!!! Watch

liemluji
Badges: 7
Rep:
?
#1
Report Thread starter 3 years ago
#1
Hi, please help me with this question

Find the length of the tangents from the point (3,-1) to the circle

x^2+y^2-10x-4y+12=0

I found out that the center of the circle is (5,2) and radius is root 17
But when I found the distance between the point (3,-1) and the center, I got root 13.

How is this possible? I was going to use pythagoras to solve the length (hyp- root 13, so it would be 13=17+x^2) which doesnt work at all.

If I did something wrong please please help me.
0
reply
razzor
Badges: 8
Rep:
?
#2
Report 3 years ago
#2
(Original post by liemluji)
Hi, please help me with this question

Find the length of the tangents from the point (3,-1) to the circle

x^2+y^2-10x-4y+12=0

I found out that the center of the circle is (5,2) and radius is root 17
But when I found the distance between the point (3,-1) and the center, I got root 13.

How is this possible? I was going to use pythagoras to solve the length (hyp- root 13, so it would be 13=17+x^2) which doesnt work at all.

If I did something wrong please please help me.
You haven't been asked to find the distance between the point (3,-1) and the centre of the circle. Find the coordinates where the tangent line passing through (3,-1) touches the circle and find the distance between the two.

edit: A scanned in copy of the whole question could be useful
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

University open days

  • University of Surrey
    All subjects except Veterinary Medicine and Guildford School of Acting Undergraduate
    Wed, 20 Nov '19
  • The University of Law
    Solicitor Series: Discover Your Type of Law - LPC and GDL - Birmingham campus Postgraduate
    Wed, 20 Nov '19
  • Buckinghamshire New University
    Postgraduate and professional courses Postgraduate
    Wed, 20 Nov '19

what's your favourite season?

Summer (62)
32.8%
Spring (35)
18.52%
Autumn/Fall (46)
24.34%
Winter (36)
19.05%
I love them all equally (10)
5.29%

Watched Threads

View All