Roger N. answered • 12/14/17
Tutor
4.9
(297)
. BE in Civil Engineering . Senior Structural/Civil Engineer
The general equation of the circle is (x-a)2+ (y-b)2 = r2 where (a,b)
represent the center of the circle point given as (-2,2)
Substitute into equation above you get (x+2)2+(y-2)2= r2
The circle passes through the point (1,-3) and therefore it is one of the solutions to the equation. substitute into equation to find r2
(1+2)2+(-2-2)2= r2 , 32+(-4)2 = r2, 9+16 = r2, and 25 = r2
Substitute r2 = 25 into the equation and it becomes
(x+2)2+(y-2)2= 25 is the equation of the circle of center (-2,2) and radius r = √25 = ±5 , and passing through the point (1,-3)
Roger N.
tutor
Jemia:
The erroe is a mathematical one. When I computed r2 I substituted the wrong number in the equation -2 and it should be -3 as the point is (1,-3)
Then r2 = (1+2)2+(-3-2)2= 32+(-5)2
= 9+25 = 34
the standard form of the equation of the circle is
(x+2)2+(y-2)2= 34 note r2= 34 rather than 25
and this should be correct. let me know if it is not
Regards
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12/15/17
Jemiah L.
12/15/17