Question

If f(x) = 4^-x, then f(a/2) =
(a) 2
(b) 1
(c) 2^1/a
(d) 1/2^a
(e) 2^a

Answer 1

Plug and play again!\[f\left({a \over 2}\right) = 4^{-{a \over 2}} \]

Answer 2

does that equal to 1/4^a/2 ?

Answer 3

Yes sir :)

Answer 4

Could be wrong, but I think it's one of those... Closest is (c)...
f(a/2)=4^(-a/2)=[4^(1/2)]^-a=2^-a

Answer 5

You could simplify that.

Answer 6

1/square root 4^a

Answer 7

Yes, and?

Answer 8

are u supposed to rationalize it?

Answer 9

Yes sir!

Answer 10

so what do u do after square root 4^a/ 4^a

Answer 11

Remember that you have\[(4^a)^{1 \over 2} \over 4^a \]Subtract exponents.

Answer 12

lol wait we are back at the point that we started with.

Answer 13

http://www.wolframalpha.com/input/?i=4%5E%28-a%2F2%29

Answer 14

4^1/2 is 2 but how did it change do 2^-a?

Answer 15

Let's check.

Answer 16

\[ 4^{-a \over 2} \implies (4^{-a})^{1 \over 2}\implies (2^{-2a})^{1 \over 2} \implies 2^{-a}\]

Answer 17

That was quick.

Answer 18

\[4^{-\frac{a}{2}}=\frac{1}{4^{\frac{a}{2}}}=\frac{1}{\sqrt{4}^a}=\frac{1}{2^a}=2^{-a}\]
how'd i do?

Answer 19

oh not so good because i didn't match it up

Answer 20

You did well, son.

Answer 21

;P

Answer 22

\[\frac{1}{2^a}=\left(\frac{1}{2}\right)^a\]

Answer 23

so is the answer (d) ?

Answer 24

Yes. lawls.

Answer 25

thanks (y)