Question

How do you write an equation for a circle with Center (−3, −6); radius 2?

Answer 1

$(x + 3) {}^{2} + (y + 6) {}^{2} = 4$

Answer 2

Solution:

/* Equation of a circle whose center (h,k) , radius = r is

(x-h)²+(y-k)² = r² */

Here ,

(h,k ) = (-3,-6),

r = 2

Therefore ,

Required equation of the circle:

[x-(-3)]² + [y-(-6)]² = 2²

=> (x+3)²+(y+6)² = 4

Or

=> x²+6x+9+y²+12y+36-4=0

=> x²+y²+6x+12y+41=0

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