Question

Exponential function

Answer 1

We can break the term
`2^(1-x)` apart using the following law of exponents:


`a^(x+y)=a^xa^y`

Applying that, we find that


`2^(1-x)=2^(1+(-x))=2^1\cdot2^(-x)=2\cdot (1)/(2^x)`

Substituting that into our original function, we have


`f(x)=-4\cdot2^(1-x)\\ f(x)=-4\cdot2\cdot (1)/(2^x)`

Which we can rewrite in the form
`f(x)=ab^x` as


`f(x)=-8\cdot\big( (1)/(2)\big)^x`

Answer 2

f(x) = -4 * 2^(1-x)
f(x) = -4 * 2^1 / 2^x
f(x) = -8 / 2^x
f(x) = -8 (1/ 2)^x

answer is B.
f(x) = -8 (1/ 2)^x