Find the standard form of the equation of the parabola with a focus at (5, 0) and a directrix at x = -5.

Question

anonymous · Answer

Center is (0,0)

anonymous · Answer

@campbell_st

campbell_st · Answer

have you sketched the focus and directrix to determine which way the parabola opens...?

anonymous · Answer

It opens right

campbell_st · Answer

there are 2 ways to do this question... 

1. use the distance formula... knowing the distance from the focus to a point on the parabola is equal to the distance from the point to the directirx. 

2. find the focal length and use a standard form of the parabola.

campbell_st · Answer

great so the standard from I use for this parabola is 

$$(y - k)^2 = 4a(x - h)$$

where (h, k) is the vertex and a is the focal length. 

any ideas on the focal length..?

anonymous · Answer

I have no idea what that is.

anonymous · Answer

wait. it's 5

anonymous · Answer

I just remembered what that was

campbell_st · Answer

ok... so it seems you have only been taught about selecting a point on the parabola.... 

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do by definition, the distance from the focus to P is equal to the distance from P to Q

I'd expect that's the way you have been taught to find the locus of the parabola.