points a(-1 y) and b(5 7) lie on a circle with centre o(2,-3y) find y
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a========O===========b
center of divide ab two equal part ,hence O is the midpoint of ab
use section formula , for y-axis
-3y=(y+7)/2
-6y=y+7
y=-1
center of divide ab two equal part ,hence O is the midpoint of ab
use section formula , for y-axis
-3y=(y+7)/2
-6y=y+7
y=-1
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Answer:
(2-(-1))² + (y-(-3y))²= (5-2)² + (7-(-3y))²
=>9+16y² =9 +(7+3y)²
=>16y²=49+9y²+42y
=>7y²-42y-49=0
=>y²-6y-7=0
=>y²-7y+y-7=0
=>y(y-7)+1(y-7)=0
(y-7)=0 or (y+1)=0
=>y=7 or y=-1
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