Maligayang pagdating sa Imhr.ca, ang pinakamahusay na platform ng tanong at sagot para sa mabilis at tumpak na mga sagot. Maranasan ang kaginhawaan ng pagkuha ng eksaktong sagot sa iyong mga tanong mula sa isang dedikadong komunidad ng mga propesyonal. Sumali sa aming Q&A platform upang kumonekta sa mga eksperto na handang magbigay ng eksaktong sagot sa iyong mga tanong sa iba't ibang larangan.

find the equation of a circle passing through (3,7) and tangent to the lines x-3y+8=0 and y=3x

Sagot :

Jers15
Lines tangent:
x-3y+8=0
y=3x

Simply substitute the values:
x-3(3x)+8=0
x-9x+8=0
-8x+8=0
Subtract both sides by 8
-8x=-8
Divide both sides by -8
x=1

Substitute the value of x:
y=3(1)
y=3

The coordinate is: (1,3) which is where it is tangent..

Both of them are endpoints of the circle so I recommend you draw a line connecting both of them, then attach, then the midpoint of it should be the center

M:((1+3)/2 , (3+7)/2)
M:(4/2 , 10/2)
M:(2,5)

Find the distance from the radius to one of its endpoints..
d=√[(x2-x1)²+(y2-y1)²]
d=√[(3-2)²+(7-5)²]
d=√[1+4]
d=√5

The center is (2,5) Now 2 is the h and 5 is the k from the equation:
(x-h)²+(y-k)²=r²
(x-2)²+(y-5)²=(√5)²
x²-4x+4+y²-10y+25=5
x²-4x+y²-10y+24=0

Hope this helps =)