A1 Which of the graphs in the images can be the graph of the function $f(x)=a x^{2}+b x+c$, where $a, b$ and $c$ are negative real numbers?
(A)

![](https://cdn.mathpix.com/cropped/2024_06_07_c987701c9bb62194911fg-06.jpg?height=280&width=221&top_left_y=931&top_left_x=284)
(B)

![](https://cdn.mathpix.com/cropped/2024_06_07_c987701c9bb62194911fg-06.jpg?height=277&width=214&top_left_y=932&top_left_x=704)
(C)

![](https://cdn.mathpix.com/cropped/2024_06_07_c987701c9bb62194911fg-06.jpg?height=277&width=220&top_left_y=935&top_left_x=1135)
(D)

![](https://cdn.mathpix.com/cropped/2024_06_07_c987701c9bb62194911fg-06.jpg?height=277&width=208&top_left_y=935&top_left_x=1575)

(E) none of the above
A1. If $a<0$, the graph of the quadratic function - a parabola is concave (has a maximum at the vertex). If $c<0$, the graph intersects the y-axis on the negative axis. Since $b<0$, the abscissa of the vertex $p=-\frac{b}{2 a}$ is negative. Figure A applies.