Is this correct?

question: Find the equation of the circle with center at (3, 2) and through the point (5, 4).

my answer:
d = √{[(3 - 5)^2] + [(2 - 4)^2]}

d = √{[-2^2] + [-2^2]}

d = √{4 + 4}

d = √8

d ≈ 2.82

(x - 3)^2 + (y - 2)^2 = 2.82^2

Question

Is this correct?

question: Find the equation of the circle with center at (3, 2) and through the point (5, 4). 

my answer:
d = √{[(3 - 5)^2] + [(2 - 4)^2]}

d = √{[-2^2] + [-2^2]}

d = √{4 + 4}

d = √8

d ≈ 2.82



(x - 3)^2 + (y - 2)^2 = 2.82^2

quickstudent · Answer

@mathmate

ambuj · Answer

yes right

welshfella · Answer

yes
but use r for the radius is better
d looks like you are working out the diameter

owen_turner · Answer

Yes.

quickstudent · Answer

I used d for distance.

welshfella · Answer

and you  can write the right side as 8

welshfella · Answer

oh ok
but it is the radius wou are calculating 
on first sight it might be confusing.

welshfella · Answer

its no big deal..

mathmate · Answer

2.82 is a crude approximation to sqrt(8).
I prefer to see the exact value (sqrt(8))^2, or simply 8 on the right hand side.
Math is not like engineering.  We try to give exact values whenever possible.

welshfella · Answer

exactly

quickstudent · Answer

I know that it's approximate, which is why I used the ≈  sign at the end. Are you saying I can write it as    (x - 3)^2 + (y - 2)^2 = (√8)^2      ?

quickstudent · Answer

Alright I think I get it anyway.

mathmate · Answer

Yes, both (sqrt(8))^2 or 8 would be acceptable to me.