The center of a circle is (2a-1, -1) and it passes through the point (-3, -1) if diameter of circle is 20. Find a
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The diameter of circle = 20
Radius of circle = 10
Radius = Distance between centre of the circle and any point lying on the circle
Radius = Distance between (2a-1,-1) & (-3,-1)
by using distance formula we get ;
20 = √[-3-(2a-1)]^2 + [-1-(-1)]^2
squaring both sides :
400 = (2a-2)^2 + 0
400 = 4a^2 +4 - 8a
100 = a^2 + 1 - 2a
a^2 -2a-99 = 0
a^2 -9a +11a -99 = 0
9a(a-9) +11(a-9) = 0
(9a+11) × (a-9) = 0
a = -11 or +9
hope this helped me,
plzzz mark as brainliest ..........!
Radius of circle = 10
Radius = Distance between centre of the circle and any point lying on the circle
Radius = Distance between (2a-1,-1) & (-3,-1)
by using distance formula we get ;
20 = √[-3-(2a-1)]^2 + [-1-(-1)]^2
squaring both sides :
400 = (2a-2)^2 + 0
400 = 4a^2 +4 - 8a
100 = a^2 + 1 - 2a
a^2 -2a-99 = 0
a^2 -9a +11a -99 = 0
9a(a-9) +11(a-9) = 0
(9a+11) × (a-9) = 0
a = -11 or +9
hope this helped me,
plzzz mark as brainliest ..........!
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