Answer:
y = 0.2(0.5)^x
Step-by-step explanation:
Exponential function are of the form
y = ab^x
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To find "a" plug in x = 0 y = 0.2
0.2 = a(0.2)^0
0.2 = a
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To find "b" plug in another point and a = 0.2
using x = 2, b = 0.05
0.05 = 0.2b^2
Divide both sides by 0.20
.25 = b^2
Take the square root of both sides
0.5 = b
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With a = 0.2 and b = 0.5 the equation becomes
y = 0.2(0.5)^x