Determine the equation of a circle whose diameter has the endpoints (-1, 2) and (7. -4).
1) (x - 3)2 + (y + 1)2 = 5
2) (x - 3)2 + (y + 1)2 = 25
3) (x - 3)2 + (y + 1)2 = 100
4) (x - 3)2 + (y + 1)2 = 10

(x - 3)^2 + (y + 1) = 25

Step-by-step explanation:

First find the midpoint of the diameter, because that represents the center of the circle.

                                                                     -1 + 7

The x-coordinate of the midpoint is xm = = 3

                                                                          2

                                                 2 - 4

and the y-coordinate is ym = = -1

                                                     2

And so the center of this circle is at (3, -1).

Use the Pythagorean Theorem to determine the square of the radius:

square of radius = 4^2 + (-3)^2 = 16 + 9 = 25

And so the equation of this circle is (x - 3)^2 + (y + 1) = 25

option 2

Step-by-step explanation:

The equation of a circle in standard form is

(x - h)² + (y - k)² = r²

where (h, k) are the coordinates of the centre and r is the radius

The centre is at the midpoint of the endpoints of the diameter.

Using the midpoint formula with (- 1, 2) and (7, - 4), then

centre = ( , ) = (3, - 1 )

The radius is the distance from the centre to either of the endpoints of the diameter.

Using the distance formula

r =

with (x₁, y₁ ) = (3, - 1) and (x₂, y₂ ) = (- 1, 2)

r =

  =

  = = = 5

Thus

(x - 3)² + (y - (- 1))² = 5² , that is

(x - 3)² + (y + 1)² = 25 ← equation of circle

answer set (b) 0.5, 3/4 80% is in order from least to greatest.  

step-by-step explanation:

in order to compare rational numbers to each other, it is much easier if they are in the same form.   typically, the best form in which to evaluate rational numbers is in decimals.   in order to convert a percent to a decimal, you would divide the given percentage by 100.   you can also accomplish the conversion by moving the decimal point over two places to the left.   for example, the decimal value of 80% is 80/100, or 0.8.   in order to convert a fraction to a decimal, you need to divide the numerator by the denominator.   for example, 3/4 is 0.75.   so, for choice (b) 0.5 3/4 (0.75), 80% (0.8) is the only choice in which the numbers are in order from least to greatest.  

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step-by-step explanation: