101k views
2 votes
Here is the equation of a circle in standard form.

(x + 10)2 + (y + 9)2 = 100

What is the radius?

A. 100
B. 50
C. 10

User Tuan Chau
by
8.7k points

2 Answers

4 votes

Answer:

c

Explanation:

OMY

I was so thrown off my the 2's

square root of 100 = 10

User Derrops
by
8.5k points
3 votes

Answer:

C

Explanation:

The equation is in the standard form for a circle:

(x-h)^2+(y-k)^2=r^2

where (h,k) is the center, and r is the radius

If we compare the 2 equations:

(x-h)^2+(y-k)^2=r^2

(x + 10)2 + (y + 9)2 = 100

We can see that r^2 is equal to 100. Let's set them equal to each other.

r^2=100

Since r is being squared, take the square root of both sides. This will cancel out the exponent.


√(r^2)=√(100)

r=10

So, our radius is 10, or choice C

User Rraphael
by
8.7k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories