WILL GIVE A MEDAL PLEASE HELP
Which of the following is the equation of a circle whose center is at the origin and whose diameter has endpoints (-1, 2) and (1, -2)?

x^2 + y^2 = 2
x^2 + y^2 = 3
x^2 + y^2 = 4
x^2 + y^2 = 5

Question

WILL GIVE A MEDAL PLEASE HELP
Which of the following is the equation of a circle whose center is at the origin and whose diameter has endpoints (-1, 2) and (1, -2)?

x^2 + y^2 = 2
x^2 + y^2 = 3
x^2 + y^2 = 4
x^2 + y^2 = 5

anonymous · Answer

Note that equation of a circle is as such $$(x-h)^2+(y-k)^2=r^2$$ where your centre is (h,k) so what will it be?

anonymous · Answer

It says the center is the origin meaning (0,0)

anonymous · Answer

I don't know, I'm so confused @iambatman

anonymous · Answer

You were given the end points, which will help you find the radius, which is 2 as the end points of the diameter are (-1,2) and (1,-2) which should give you a diameter of 4. You also know the center since it mentions center is at the origin meaning (0,0). $$(x-0)^2+(y-0)^2=2^2$$

alekos · Answer

I think the diameter  is 2sqrt5