基礎math-u03-d02
The graph of y = ax^2 + bx + c with a > 0 is:
A. A parabola that opens upwards and has a minimum✓ 答案
B. A parabola that opens downwards and has a maximum
C. A straight line
D. A circle
解說
The sign of the leading coefficient decides the direction the parabola opens. With a > 0 the graph has a minimum; with a < 0 it has a maximum.