Question
Mathematics Question on Circle
Does the point (−2.5,3.5) lie inside, outside, or on the circle x2+y2=25 ?
Answer
The equation of the given circle is
x2+y2=25
⇒(x−0)2+(y−0)2=52,
which is of the form
(x−h)2+(y−k)2=r2,
where h=0 , k=0, and r=5.
∴Centre =(0,0)and radius =5
Distance between point (-2.5, 3.5) and center (0, 0)
=√[(−2.5–0)2\+(−3.5–0)2]
=√(6.25+12.25)
=√18.5
=4.3 [which is <5]
Since, the distance between the point (−2.5,−3.5) and the center (0,0) of the circle is less than the radius of the circle, the point (−2.5,−3.5) lies inside the circle.