Acircle in the xy-plane has a diameter with endpoints whose coordinates are negative 1 comma negative 3 and 7 comma 3. if the point with coordinates 0 comma b lies on the circle and b is greater than 0, what is the value of b ?

First we look for the coordinates of the center of the circle. For this, we use the following formula:

 ((x1 + x2) / 2, (y1 + y2) / 2)

 Where,

 (x1, y1) = (- 1, -3)

 (x2, y2) = (7, 3)

 Substituting values we have:

 ((-1 + 7) / 2, (-3 + 3) / 2)

 ((6) / 2, (0) / 2)

 (3, 0)

 We are now looking for the diameter of the circle. For this we use the formula of distance between points:

 d = root ((x2-x1) ^ 2 + (y2-y1) ^ 2)

 Substituting values:

 d = root ((7 - (- 1)) ^ 2 + (3 - (- 3)) ^ 2)

 d = 10

 Then, the radius of the circle is:

 r = d / 2 = 10/2

 r = 5

 The circle equation will be

 (x-h) ^ 2 + (y-k) ^ 2 = r ^ 2

 Where,

 (h, k) = (3, 0)

 r = 5

 Substituting

 (x-3) ^ 2 + (y-0) ^ 2 = 5 ^ 2

 Substituting

 (x, y) = (0, b)

 (0-3) ^ 2 + (b-0) ^ 2 = 5 ^ 2

 b = root (25-9)

 b = root (16)

 b = 4

 Answer

 the value of b is

 b = 4

answer is because 4×10=40

and 98×4= is 392

40,392

the answer would be d.

step-by-step explanation:

move all variables to the left side and all constants to the right side

(x−3)^2+(y−1)^2=16

this is the form of a circle. use this form to determine the center and radius of the circle.

( x − h ) 2 + ( y − k ) 2 = r 2

match the values in this circle to those of the standard form. the variable   r   represents the radius of the circle,   h   represents the x-offset from the origin, and   k   represents the y-offset from origin.

r = 4

h = 3

k = 1

the center of the circle is found at   ( h , k ) .

center:   ( 3 , 1 )

these values represent the important values for graphing and analyzing a circle.

center:   ( 3 , 1 ).

radius:   4