The circle, question help!!!?

Question

1. Write the equation of a circle with centre (0, -4) and radius of 2
2. Determine the equation of a circle with centre (-2, 5) which passes through (-1, 8).
3. Determine the equation of the circle that has a diameter with endpoints (-8, 5) and (2, 3).

Answer 1

1)Given that equation of circle has centre (0 , -4) and radius 2.

2)Given that circle has centre (-2 , 5) and passing through (-1 , 8)

Therefore the required equation of circle is

3)Given that circle has diameter has endpoints  (-8 , 5) and passing through (2 , 3)

(-3 , 4)

Now find the distance between (-8 , 5) and (2 , 3)

Therefore the required equation of circle is

Comments

Coorect answer for  third question :

Circle equation is .

Answer 2

3) Standard form of circle equation is

Where r is radius and center (h, k).

Given that circle has diameter has endpoints  (-8 , 5) and  (2 , 3)

Circle center is mid point of the diameter end points.

Now find the distance between center and any of the end point and this would be the radius of circle.

Distance between (2, 3) and (-3, 4)

Therefore, the circle equation is