Question 769061
how do I find the equation of the circle that satisfy this conditions?: 
endpoints of diameter are P(-1,1) and Q(5,9)
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Standard form of equation for a circle:{{{(x-h)^2+(y-k)^2=r^2}}}, (h,k)=(x,y) coordinates of center, r=radius
Use distance formula to find radius: diameter=√(x1-x2)^2+(y1-y2)^2)=√((5+1)^2+(9-1)^2)=√36+64
=√100=10
radius=10/2=5
coordinates of center=midpoint of given points: (-1,1) and (5,9)
midpoint=(x1+x2)/2,(y1+y2)/2=(-1+5)/2),(9+1)/2)=(2,5)
center: (2,5)
Equation of given circle:
{{{(x-2)^2+(y-5)^2=25}}}