Question

28. Write the equation of a circle having center at (2, 3) and radius is 4
units.​

Answer 1

Answer:

The equation of a circle with center (h,k) and radius r is given by:

(x−h)2+(y−k)2=r2

Here, h = 2, k = -3 and r = 4. Substitute all these values in the above equation.

(x−2)2+(y−(−3))2=42

⟹(x−2)2+(y+3)2=16

Expanding,

⟹(x2+22−2×x×2)+(y2+32+2×y×3=16

[∵(a+b)2=a2+b2+2ab]

⟹x2+y2−4x+6y+4+9−16=0

⟹x2+y2−4x+6y−3=0