Question

a general formula for a parabola is $y^2 = 4px$. what is the value of $p$ in the equation $y^2 = -4x$? $\bigcirc$ $p = -4$ $\bigcirc$ $p = -1$ $\bigcirc$ $p = 1$ $\bigcirc$ $p = 4$

Explanation:

Step1: Compare the given equation with the general formula

The general formula for the parabola is \( y^{2}=4px \), and the given equation is \( y^{2}=-4x \). We can rewrite the given equation to match the form of the general formula. So, \( y^{2}=4\times(-1)x \).

Step2: Identify the value of \( p \)

By comparing \( y^{2}=4\times(-1)x \) with \( y^{2}=4px \), we can see that \( 4p=-4 \). Solving for \( p \), we divide both sides of the equation \( 4p = - 4 \) by 4, which gives \( p=\frac{-4}{4}=-1 \).

Answer:

B. \( P = - 1 \)