Answer:
8.5
Step-by-step explanation:
The last option: In his recursive formula, he should have the term an−1 instead of −4 to get an=an−1−3.
y = −1/4x^2 + 4x − 19
1. Use x = -b/2a to find x.
x = -4/2(-1/4)
x = -4/(-1/2)
x = -4/1 • (-2/1)
x = 8/1
x = 8
2. Plug x into the function to find your vertex.
Replace every x you see in the function with 8 and do the math.
Take it from here.