Question

select the graphs that have an equation with a < 0.

Explanation:

Step1: Recall parabola direction rule

For a quadratic function \( y = ax^2+bx + c \), if \( a>0 \), the parabola opens upward; if \( a < 0 \), it opens downward.

Step2: Analyze each graph

• First graph: Opens upward (U - shaped), so \( a>0 \).
• Second graph: Opens downward (n - shaped), so \( a < 0 \).
• Third graph: Opens downward (n - shaped), so \( a < 0 \).
• Fourth graph: Opens upward (U - shaped), so \( a>0 \).

Answer:

The graphs with \( a < 0 \) are the second graph (blue parabola) and the third graph (purple parabola with vertex at (0,4)).