Question 623929
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi, 
Find the equation of the circle whose diameter has endpoints (-9, -2) and (1, 1).
With conics: Highly recommend SKETCHING All info given and continue sketching with info found. 
I.  Plot given Points
II. Find the Midpoint Pt(x,y):  ( {{{(x[1] + x[2])/2}}}, {{{(y[1] + y[2])/2  )}}})which will be the Center of this circle
(-9, -2) and 
(1, 1)  Midpoint = ((-9+1)/2, (-2+1)/2)) = (-4,-1/2)  III.  Plot Midpoint
(-4,-1/2)  D = r = {{{sqrt(5^2 + (3/2)^2)= sqrt(27.25) =  5.22}}}
x+4)^2 + (y + .5)^2 = 27.25
{{{drawing(300,300,   -10,10,-10,10, 
 grid(1),
circle(-9, -2,0.4),
circle(1, 1,0.4),
circle(-4,-.5,0.4),
circle(-4,-.5,5.22),
graph( 300, 300, -10,10,-10,10))}}}