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Circles help

Hi, I was wondering if anyone could help me on part of this question? Here's the information ive already been given/worked out: the points P (9,3) and Q (1,-3) lie at opposite ends of a circle - radius=5, centre= (5,0) equation of circle= (x-5)^2 + (y-0)^2 = 5^2
Describe a geometrical transformation by which C can be obtained from the circle with the equation x^2 + y^2 = r^2
I don't really get this...is it just 5^2 - 0^2 = 5^2? I don't get what I'm supposed to be writing :s-smilie:
Thanks in advance!
Reply 1
Avatar for TenOfThem
TenOfThem
18
Are you sure that it is

x2+y2=r2x^2 + y^2 = r^2
Reply 2
Avatar for TenOfThem
TenOfThem
18
Do you know what transformation is needed to go from f(x) to f(x-5)
Reply 3
Avatar for georgiaaaxo
georgiaaaxo
OP
8
Original post by TenOfThem
Do you know what transformation is needed to go from f(x) to f(x-5)


in regards to your first post, yes it definitely says in the question: describe the geometrical transformation by which C can be obtained from the circle with the equation x^2 +y^2= r^2

and yeah, that would be a translation by vector (5,0) right?
is that what it is, because thats the coordinates of the centre? not sure how to use x^2 +y^2= r^2 with it though :s-smilie:
Reply 4
Avatar for TenOfThem
TenOfThem
18
So, to go from x2+y2=52x^2 + y^2 = 5^2

to (x−5)2+y2=52(x-5)^2 + y^2 = 5^2

would be a translation as you say

How might you transform a circle radius = 1 to a circle radius = 5
Reply 5
Avatar for georgiaaaxo
georgiaaaxo
OP
8
Original post by TenOfThem
So, to go from x2+y2=52x^2 + y^2 = 5^2

to (x−5)2+y2=52(x-5)^2 + y^2 = 5^2

would be a translation as you say

How might you transform a circle radius = 1 to a circle radius = 5


ermmmmmmm an enlargement? scale factor 5? thats a complete guess aha:/

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