For f(x) = 86 × (0.2)ˣ, find f(2):
A1.72
B3.44
C17.2
D86
Answer & Solution
Correct answer: B. 3.44
f(2) = 86 × (0.2)² = 86 × 0.04 = 3.44. (Equivalent: 86 × 1/25 = 86/25 = 3.44.) Notice each step decreases by 80%: f(0)=86, f(1)=17.2, f(2)=3.44.
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