Question

Help me please, i need it fast

Answer 1

Answer:

2)  C.  (x - 3)² + (y + 2)² = 25

5)   x² +  y² - 8x - 16y + 54 = 0

6)   x² + y²  - 10x - 12y + 36  = 0

Explanation:

2)

center of circle = 3, -2

                            x1, y1

end point of circle = 7, 1

                                 x2, y2

 

the equation of a circle is Pythagorean theorem

x² + y² = r²    (where r is the radius of a circle)

distance between points  

(x2 - x1)² + (y2 - y1)² = r²

(7 - 3)² + (1 - (-2))² = r²

r² = 25

therefore the equation to the circle is

(x - 3)² + (y + 2)² = 25

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5)

write the general form of a circle with the center (4,8)

and containing the point (-1, 7)

distance between points  

(x2 - x1)² + (y2 - y1)² = r²

(-1 - 4)² + (7 - 8)² = r²

r² = 26

(x - 4)² + (y - 8)² = 26

(x - 4)(x - 4) +  (y - 8)(y - 8) = 26

x² - 8x + 16 + y² - 16y + 64 -26 = 0

x² +  y² - 8x - 16y + 54 = 0

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6)

find the general form of a circle with center (5,6)

and tangent to the y-axis.

           

center (5,6)

           h, k

radius = r²

r = 5

(x - h)² + (y - k)² = r²

(x - r)² + (y - k)² = r²

(x - 5)(x - 5) + (y - 6)(y - 6) = r²

x² - 10x + 25 + y² - 12y + 36 = 25

x² + y²  - 10x - 12y + 36  = 0

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