Mathematics for IGCSE & O level - Sketching Curves (Section 5 - No. 5)
Which value determines whether a parabola opens upwards or downwards?
The y-intercept
The sign of the coefficient of x^2
The x-intercepts
The vertex's x-coordinate
Explicació
The sign of the coefficient of x^2 in a quadratic equation defines the direction of the parabola.