Answer:
a = -4/9
Step-by-step explanation:
For a function y = ax² + bx + c, the maximum value is at x = -b/(2a).
f(x) = ax² − 4x + 3
Here, the maximum value is at x = -(-4)/(2a) = 2/a. Setting f(x) = 12 at this point:
12 = a (2/a)² − 4 (2/a) + 3
12 = 4/a − 8/a + 3
9 = -4/a
a = -4/9
