Question

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?

Answer 1

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....

Answer 2

Hope this answer will help you......

May God bless you,