Question 584835: Write the equation of the circle in standard form. Find the center, radius, intercepts, and graph the circle. x^2+y^2-4x-8y+4=o Answer by lwsshak3(11628) (Show Source):
You can put this solution on YOUR website! Write the equation of the circle in standard form. Find the center, radius, intercepts, and graph the circle. x^2+y^2-4x-8y+4=0
complete the square
(x^2-4x+4)+(y^2-8y+16)=-4+4+16
(x-2)^2+(y-4)^2=16
center: (2,4)
radius: √16=4
..
x-intercept
set y=0
x^2-4x+4=0
(x-2)^2=0
x=2 (multi. 2)
..
y-intercepts
set x=0
y^2-8y+4=0
solve by quadratic formula
a=1, b=-8, c=4
y=[8±√(64-4*1*4)]/2*1
y=[8±√48]/2=[8±6.928]/2=1.072/2 or 14.92802=.536 and 7.464
y≈0.536
and
y≈7.464
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