Question

22.  What is an equation of the parabola with vertex at the origin and focus (−4, 0)?

Answer 1

The correct answer for the question shown above is the second option (Option b), and the option cwhich is:

 b) x = -1/16y^2
 c) y=-1/16x^2

 The explanation is shown below:

 The focus of a parabola is (h,k+1/4a), then, you have:

 h,k= (0,0)
 1/4a=1/4(-1/16)

 Then, you obtain:

 1/4a=-4

 Therefore, the focus of the equation of the parabola x = -1/16y^2 and the parabola y=-1/16x^2 is F(0-4)

 So, as you can see, the correct answer is the options mentioned before, the option b and the option c.