noTh1ng wrote:
Hi,
i don't understand from
Bunuels solution how we come up with the value of S in statement 1 in order to answer what r^2 + s^2 is?
r^2 equals 4, that is all clear, but s should be y-value, how do we get that?
Hi
noTh1ng,
In the xy-plane, point (r, s) lies on a circle with center at the origin. What is the value of r^2 + s^2?
(1) The circle has radius 2
(2) The point (2√, −2√) lies on the circle
You seem to have misunderstood a little here.
The equation of Circle is given by \(x^2 + y^2 = Radius^2\)
Given : (r,s) lie on the circlei.e. (r,s) will satisfy the equation of Circle
i.e. \(r^2 + s^2 = Radius^2\)
Question : Find the value of \(r^2 + s^2\)? but since \(r^2 + s^2 = Radius^2\) therefore, the question becomes
Question : Find the value of \(Radius^2\)?Statement 1: The circle has radius 2i.e. \(r^2 + s^2 = Radius^2 = 2^2 = 4\)
SUFFICIENTStatement 2: The point (√2, −√2) lies on the circlei.e. (√2, −√2) will satisfy the equation of circle
i.e.
(√2)^2 + (−√2)^2 = Radius^2i.e. Radius = 4
hence, \(r^2 + s^2 = Radius^2 = 2^2 = 4\) Hence,
SUFFICIENTAnswer: Option D
I hope it helps!
Please Note: You have been confused r (X-co-ordinate) and r (Radius) as it seems from your question