the centre of a circle is (2a-1 , 7) and it passes through the point (-3 , -1) if the diameter of circle 20 units, then find the valve of a?
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Answered by
104
Answer:
2 or -4
Step-by-step explanation:
Since the circle with centre (2a-1, 7) passes through the point (-3,-1)
The Distance between (2a-1, 7) and (-3, -1) is the Radius of the circle...
It's Given that:
Diameter = 20 units
Therefore,
Radius = 10 units
By Distance Formula (Co-ordinate Geometry):
10. =sqrt{(2a-1 -(-3))^2 + (7-(-1))^2}
100=(2a+2)^2 + 64
100=(2a)^2 + 4 + 8a +64
100=4a^2 + 8a +68
0=4a^2 + 8a -32
0=4a^2 +16a-8a -32
0=4a(a+4)-8(a+4)
0=(4a - 8)(a + 4)
Therefore,
a=8/4. Or. (a = - 4)
(a=2)
So theres your answer....
Answered by
54
Hope this answer will help you......
May God bless you,
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