Question

what is the radius of the circle with the equation $(x - 10)^2+(y + 3)^2 = 1$?
a. 2
b. 1
c. 10
d. 0.5

Explanation:

Step1: Recall circle - equation formula

The standard form of a circle's equation is $(x - a)^2+(y - b)^2=r^2$, where $(a,b)$ is the center of the circle and $r$ is the radius.

Step2: Compare given equation with standard form

Given $(x - 10)^2+(y + 3)^2 = 1$, we can rewrite it as $(x - 10)^2+(y-(- 3))^2=1^2$. Here, $r^2 = 1$, so $r = 1$.

Answer:

B. 1