Question

consider the following equation of a circle. (x - 1)^2+(y + 2)^2 = 25 step 2 of 3: find the radius, r. answer how to enter your answer (opens in new window)

Explanation:

Step1: Recall circle - equation formula

The standard form of the equation of a circle 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 $(x - 1)^2+(y + 2)^2 = 25$, we can rewrite it as $(x - 1)^2+(y-(- 2))^2=5^2$. Since $r^2 = 25$, then $r=\sqrt{25}$.

Answer:

$5$