Question

find the equation of the circle with the given center and radius:• Center (0,0) and r = √10• Center (-9,-8), and r = 4

Answer 1

QuESTION 1

step 1: Concept

To write equation of a circle, you must have a center and radius.

Step 2: Write the equation of a circle formula

$\begin{gathered} (x-a)^2+(y-b)^2=r^2 \\ \\ \text{Center = (0.0) and radius = }\sqrt[]{10} \end{gathered}$

Step 3: Substitute it to the equation

Final student.

a = 0 and b = 0

$\begin{gathered} (x-0)^2+(y+4)^{2^{}}\text{ = (}\sqrt[]{10})^2 \\ x^2+y^2\text{ = 10} \end{gathered}$

Question 2

Center = (-9, -8)

radius r = 4

Substitute a = -9 , b = -8 and r = 4 in the equation.

$\begin{gathered} (x-a)^2+(y-b)^2=r^2 \\ (x+9)^2+(y+8)^2=4^2 \\ (x+9)^2+(y+8)^2\text{ = 16} \end{gathered}$