Explore a world of knowledge and get your questions answered on IDNLearn.com. Our community provides timely and precise responses to help you understand and solve any issue you face.

Select the correct answer.

Which point lies on the circle represented by the equation [tex]$x^2+(y-12)^2=25^2$[/tex]?

A. [tex]$(20, -3)$[/tex]
B. [tex][tex]$(-7, 24)$[/tex][/tex]
C. [tex]$(0, 13)$[/tex]
D. [tex]$(-25, -13)$[/tex]


Sagot :

To determine which point lies on the circle represented by the equation [tex]\( x^2 + (y-12)^2 = 25^2 \)[/tex], we need to check each given point against the circle’s equation.

The general form of a circle's equation is [tex]\( (x-h)^2 + (y-k)^2 = r^2 \)[/tex], where [tex]\((h, k)\)[/tex] is the center of the circle, and [tex]\( r \)[/tex] is the radius.

For this specific equation:
- The center of the circle [tex]\((h, k)\)[/tex] is [tex]\((0, 12)\)[/tex].
- The radius [tex]\( r \)[/tex] is [tex]\( 25 \)[/tex].

We will check each point.

### Point A: [tex]\((20, -3)\)[/tex]
1. Calculate [tex]\( x^2 \)[/tex]:
[tex]\[ 20^2 = 400 \][/tex]
2. Calculate [tex]\( (y - 12)^2 \)[/tex]:
[tex]\[ (-3 - 12)^2 = (-15)^2 = 225 \][/tex]
3. Add these together:
[tex]\[ 400 + 225 = 625 \][/tex]

Since [tex]\( 625 = 25^2 \)[/tex], point A [tex]\((20, -3)\)[/tex] lies on the circle.

### Point B: [tex]\((-7, 24)\)[/tex]
1. Calculate [tex]\( x^2 \)[/tex]:
[tex]\[ (-7)^2 = 49 \][/tex]
2. Calculate [tex]\( (y - 12)^2 \)[/tex]:
[tex]\[ (24 - 12)^2 = 12^2 = 144 \][/tex]
3. Add these together:
[tex]\[ 49 + 144 = 193 \][/tex]

Since [tex]\( 193 \neq 625 \)[/tex], point B [tex]\((-7, 24)\)[/tex] does not lie on the circle.

### Point C: [tex]\((0, 13)\)[/tex]
1. Calculate [tex]\( x^2 \)[/tex]:
[tex]\[ 0^2 = 0 \][/tex]
2. Calculate [tex]\( (y - 12)^2 \)[/tex]:
[tex]\[ (13 - 12)^2 = 1^2 = 1 \][/tex]
3. Add these together:
[tex]\[ 0 + 1 = 1 \][/tex]

Since [tex]\( 1 \neq 625 \)[/tex], point C [tex]\((0, 13)\)[/tex] does not lie on the circle.

### Point D: [tex]\((-25, -13)\)[/tex]
1. Calculate [tex]\( x^2 \)[/tex]:
[tex]\[ (-25)^2 = 625 \][/tex]
2. Calculate [tex]\( (y - 12)^2 \)[/tex]:
[tex]\[ (-13 - 12)^2 = (-25)^2 = 625 \][/tex]
3. Add these together:
[tex]\[ 625 + 625 = 1250 \][/tex]

Since [tex]\( 1250 \neq 625 \)[/tex], point D [tex]\((-25, -13)\)[/tex] does not lie on the circle.

Thus, the correct answer is:

A. [tex]\((20,-3)\)[/tex]