Find the equation to the circle such that the points A(-3,5) and B(4,-2) form the ends of a diameter?

this is all the given information.

1 Answer
Mar 25, 2018

(x-1/2)^2+(y-3/2)^2=49/2

Explanation:

"the standard form of the equation of a circle is "

color(red)(bar(ul(|color(white)(2/2)color(black)((x-a)^2+(y-b)^2=r^2)color(white)(2/2)|)))

"where "(a,b)" are the coordinates of the centre and r is"
"the radius"

"Given the endpoints of the diameter then the centre is "
"at the midpoint and the radius is the distance from the "
"centre to one of the endpoints"

"the coordinates of the midpoint are the average of the"
"the coordinates of the endpoints"

"midpoint "=[1/2(-3+4),1/2(5-2)]=(1/2,3/2)

"to calculate the radius use the "color(blue)"distance formula"

•color(white)(x)r=sqrt((x_2-x_1)^2+(y_2-y_1)^2)

"let "(x_1,y_1)=(1/2,3/2)" and "(x_2,y_2)=(-3,5)

rArrr=sqrt((-3-1/2)^2+(5-3/2)^2

color(white)(r)=sqrt(49/4+49/4)=sqrt(98/4)

rArr(x-1/2)^2+(y-3/2)^2=(sqrt(98/4))^2

rArr(x-1/2)^2+(y-3/2)^2=49/2larrcolor(red)"equation of circle"