### Home > INT3 > Chapter 5 > Lesson 5.2.1 > Problem5-61

5-61.

Write the equation in graphing form of each circle described below.

1. A circle with radius $12$ centered at the point $(–2, 13)$.

$(x − h)^2 + (y − k)^2 = r^2$

$(x + 2)^2 +(y \ – \ 13)^2 = 144$

2. A circle with center $(–1, –4)$ and radius $1$.

Refer to the hint in part (a).

3. A circle with equation $x^2 + y^2 – 6x + 16y + 57 = 0$. (Hint: Complete the square for both $x$ and $y$.)

$(x^2-6x+?)+(y^2+16y+?)=-57$

$(x^2-6x+9)+(y^2+16y+64)=-57+9+64$

Factor the expressions in parentheses and simplify.