Question

Which function is graphed here?
A) y = 2^x - 1
B) y = 2^(x - 1)
C) y = 2^x + 1
D) y = 2^(x + 1)

Answer 1

The answer is choice A) y = 2^x - 1

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Explanation:

Note how the curve goes through (0,0). So this means that plugging in x = 0 should lead to y = 0. Let's see which choices do that for us

choice A) y = 2^x - 1 = 2^0 - 1 = 1-1 = 0
choice B) y = 2^(x - 1) = 2^(0 - 1) = 2^(-1) = 0.5
choice C) y = 2^x + 1 = 2^0 + 1 = 1+1 = 2
choice D) y = 2^(x + 1) = 2^(0 + 1) = 2^1 = 2

Only choice A has x = 0 lead to y = 0, which is why choice A is the answer