The general equation given is x^2 - 4x + y^2 = -3. Transform this to an equation of a circle of the form x^2 + y^2 = r^2.
Use completing the square method:
x^2 - 4x + 4 + y^2 = -3 + 4
(x - 2)^2 + y^2 = 1
the center of the circle is (2,0) and r = 1
To check if it intersects the y axis, find the value of the x-intercept.
Do you have the rest of the question?
Answer:
B
Step-by-step explanation:
The vertex is the turning point of the parabola.
First find the zeros by equating y to zero, that is
(x - 6)(x + 12) = 0
Equate each factor to zero and solve for x
x - 6 = 0 ⇒ x = 6
x + 12 = 0 ⇒ x = - 12
The vertex lies on the axis of symmetry which is situated at the midpoint of the zeros, thus
=
=
= - 3
Thus the x- coordinate of the vertex is x = - 3 → B