The equation of a circle with F as the center and ab as the diameter is______ .

The equation of a circle with F as the center and ab as the diameter is______ .

∵ y2 = 4x, ∵ P = 2, f (1, 0), substituting x = 1 into the parabolic equation, y = ± 2 ∵ a (1, 2), B (1, - 2), ∵ ab | = 2 + 2 = 4 ∵ the equation of the circle is (x-1) 2 + y2 = 4. So the answer is: (x-1) 2 + y2 = 4