A general formula for a parabola is y2=4px.What is the value of p in the equation y2=−4x?

Compare the given equation, y² = −4x, with the standard form y² = 4px. The coefficient of x is −4, so 4p = −4; dividing both sides by 4 gives p = −1. Therefore, the correct choice is P = −1.

AI-written and checked against the verified answer.