Question

Consider the following equation of a parabola.0-7 =-4r -3)Step 2 of &: Find the directrix of the parabola.

Answer 1

Answer: x=4

For any given equation of a parabola,

`(y-k)^2=4p(x-h)`

The directrix is found at x = h-p

From the given equation,

`(y-7)^2=-4(x-3)`

We know that 4p=-4. With this, we solve for p:

`\begin{gathered} 4p=-4 \\ p=-(4)/(4) \\ p=-1 \end{gathered}`

The directrix would then be:

`\begin{gathered} x=h-p \\ x=3-(-1) \\ x=3+1 \\ x=4 \end{gathered}`