What is the equation of the circle whose diameter is 10 cm and the equations of two of its diameters are x+y=0 and x-y=0?

  1. A. x^{2}+y^{2}=1
  2. B. x^{2}+y^{2}=25
  3. C. x^{2}+y^{2}=100
  4. D. x^{2}+y^{2}-2x-2y-23=0

Correct Answer: B. x^{2}+y^{2}=25

Explanation

The center of the circle is the intersection of its diameters, x+y=0 and x-y=0, which is (0,0). The diameter is 10, so the radius is r = 5. The equation of the circle is (x-0)^2 + (y-0)^2 = 5^2 \implies x^2+y^2=25.

Related questions on Analytical Geometry (2D)

Practice more NDA Mathematics questions