Find an equation of the circle with the following characteristics and

sketch its graph.


center (0, 5), contains (0, 0)


diameter endpoints are (2, 5) and (0, 3)


tangent to x -axis, r =4, contains (–5,8)


center on x =3, tangent to y -axis at (0, 5)

Respuesta :

To answer that question we will use the general circumference equation, and the established condition in each case

That is:    ( x - h )² + ( y - k )² = r²

Solutions are:

a) x² + ( y - 5 )² = 25

b) (x - 1)² + ( y - 4 )² = 2

c)( x + 5 )² + ( y - 4 )² = 16

d)( x - 3 )² + ( y - 5 )² = 9

In the equation : ( x - h )² + ( y - k )² = r²

r is radius of the circumference  C ( h ; k )  are center coordinates

a) C ( 0 ; 5 ) contains P ( 0;0)

Then |CP| is radius   CP = [ 0-0 ; 0-5 ]  CP = ( 0 ; -5 )

|CP| = √ 0 + (-5)²  

|CP| = r = 5

Then     ( x - h )² + (y - k )² = r²    becomes

( x - 0 )² + ( y - 5 )² = (5)²

x² + ( y - 5 )² = 25

b) Diameter endpoints  P ( 2 ; 5 ) Q ( 0 ; 3)

PQ = [ 0 - 2 ; 3 - 5 ) = [ -2 ; -2 ]

|PQ| = √(-2)² + (-2)²  =  2×√2

then radius is  |PQ|/2         r = √2

Midle point ( center )   C = [ (x₁ + x₂)/2 : y₁ + y₂)/2]

C = [ (2 + 0) /2 ; ( 5+ 3 )/2 ]

C = ( 1 ; 4 )

Then  

(x - 1)² + ( y - 4 )² = 2

c) Tangent to x-axis  r = 4  and point  ( -5 ; 8 )

From attached file ( C) we can see:

C ( -5 ; 4 )  and diameter endpoints are P ( -5 0 )  and  Q ( -5 ; 8 )

The equation is :

( x -(-5) )² + ( y - 4 )² = 16

( x + 5 )² + ( y - 4 )² = 16

d)

Center on x = 3 tangent to y-axis at P ( 0;5)

If the circumference is tangent to y-axis then r = 3

Again from the attached file (D) the red line mark two endpoints diameter

C = ( 3 ; 5 )

Then the equation is:

( x - 3 )² + ( y - 5 )² = 9

Related Link: https://brainly.com/question/23988015

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