Question

PLEASE HELP!
Which of the following exponential functions goes through the points (1, 12) and (2, 36)?

f(x) = 4(3)−x
f(x) = 3(4)−x
f(x) = 3(4)x
f(x) = 4(3)x

Answer 1

points (1, 12) and (2, 36)

Plug in x=1, and then x=2, into each of the given functions.

Answer 2

KK

Answer 3

I just got (11,10) for the first two and than (12,24) for that last two

Answer 4

That doesn't make sense...

First function:
what is the value you get when you plug in x=1?

And x=2?

Answer 5

4(3)-1 =11
4(3)-2 =10

Answer 6

Isn't the x an exponent...? What you did is not using exponents.

Answer 7

Right! you right!
12 for x=1 and 36 for x=2

Answer 8

Remember how to deal with negative exponents? Or you can just use a calculator, but you aren't following order of operations
\[\large 4(3)^{-1}= 4\left( \frac{ 1 }{3 } \right)=\]

Answer 9

\[\large 4(3)^{-2 } = 4\left( \frac{ 1 }{ 3^2 } \right)=\]

Answer 10

1.3333 and 0.4444 is what my caulator gave me

Answer 11

Good, so does that look like a correct choice? Remember you're looking for the one that matches "points (1, 12) and (2, 36)"

Answer 12

well no that doesn't. wouldn't
3(4) be the same so A and B out out right?

Answer 13

B would not be the same. For B:

what is the value you get when you plug in x=1?

And x=2?

Answer 14

0.75 and 0.1875

Answer 15

Now do C and D.

Answer 16

12 and 48 for C
12 and 36 for D

Answer 17

therefore D is correct right?

Answer 18

Yes.

Answer 19

Thank you!

Answer 20

Welcome!