Question

Determine whether the graph of y = −5x2 + 3x + 8 opens up or down and whether it has a maximum or minimum point.

Answer 1

yes

Answer 2

The standard form of a Quadratic function is \[f (x) = aX ^{2} + b X + c\]
Whether curve opens upward or downward depends on the sing of "a". If "a" is positive then the curve opens up. If "a" is negative then curve opens down.



If it opens up then the vertex is the lowest point in the curve. So it is the minimum point has minimum value. If the curve opens down, the vertex is the highest point. So it is the maximum point and has maximum value