Question

From my act prep guide I need this practice problem answeredcalc subject

Answer 1

The standard form of the equation of a circle with centre (a,b) and radius r, is:

`(x-a)^2+(y-b)^2=r^2`

From the question, we provided with the following;

`\begin{gathered} \text{diameter}=8\text{units} \\ \text{ Recall that:} \\ \text{Radius}=(diameter)/(2) \\ R=(8)/(2)=4\text{units} \\ \\ \text{Centre (a,b)=(2,-4)} \end{gathered}`

Thus, we have:

`\begin{gathered} (x-2)^2+(y-(-4))^2=4^2 \\ (x-2)^2+(y+4)^2=16 \end{gathered}`

Hence, the equation of the circle is:

`(x-2)^2+(y+4)^2=16`