What are the coordinates of the center and length of
the radius of the circle whose equation is
x²+y²+2x-16y+49=0?
1) center (1,-8) and radius 4
2) center (-1,8) and radius 4
3) center (1,-8) and radius 16
4) center (-1,8) and radius 16



Answer :

The equation of the circle given is x² + y² + 2x - 16y + 49 = 0. To find the center and radius of the circle, we need to rewrite the equation in the standard form: (x - h)² + (y - k)² = r², where (h, k) is the center of the circle and r is the radius. First, complete the square for the x and y terms in the equation: x² + 2x + y² - 16y = -49 (x² + 2x + 1) + (y² - 16y + 64) = -49 + 1 + 64 (x + 1)² + (y - 8)² = 16 (x + 1)² + (y - 8)² = 4² Now, we can see that the center of the circle is (-1, 8) and the radius is 4. Therefore, the correct answer is: 2) center (-1, 8) and radius 4