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anonymous
 one year ago
HELP ME PLEASE
Which of the following exponential functions goes through the points (1, 6) and (2, 12)?
f(x) = 3(2)x
f(x) = 2(3)x
f(x) = 3(2)−x
f(x) = 2(3)−x
anonymous
 one year ago
HELP ME PLEASE Which of the following exponential functions goes through the points (1, 6) and (2, 12)? f(x) = 3(2)x f(x) = 2(3)x f(x) = 3(2)−x f(x) = 2(3)−x

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ybarrap
 one year ago
Best ResponseYou've already chosen the best response.2Plug in x=1 and see if it equals 6 Plug in x=2 and see if it equals 12 Make sense?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0not really? can you guide me through it? (xD I dont want to be an answerhogger/wanter.. I dont want the answer, just explanations :) ) @freckles

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Do you understand that coordinates are in the form (x,y)?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0What don't you understand?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1If \[\Large f(x) = 7(3)^x\] (for example), then what is the value of f(x) when x = 2? In other words, what is f(2) equal to?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0f(2)=441?? #CONFUSED

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1Replace each x with 2 \[\Large f(x) = 7(3)^x\] \[\Large f(2) = 7(3)^2\] \[\Large f(2) = 7(9)\] \[\Large f(2) = 63\] Do you see how I got f(2) to be equal to 63?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1btw you square first and then you multiply

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok, I forgot that rule :) (like DUHR, Bella, get a grip)

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1Since \(\Large f({\color{red}{2}}) = {\color{blue}{63}}\) from my example, this means the point \(\Large ({\color{red}{x}},{\color{blue}{y}})=({\color{red}{2}},{\color{blue}{63}})\) lies on the function curve of f(x)

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0\(f(x)=y= \begin{cases} 3(2)^x\\ 2(3)^x\\ 3(2)^{x}\\ 2(3)^{x} \end{cases}\qquad \qquad \begin{array}{llll} x&y \\\hline\\ {\color{brown}{ 1}}&3(2)^{\color{brown}{ 1}}\\ &2(3)^{\color{brown}{ 1}}\\ &3(2)^{{\color{brown}{ 1}}}\\ &2(3)^{{\color{brown}{ 1}}}\\ {\color{brown}{ 2}}&3(2)^{\color{brown}{ 2}}\\ &2(3)^{\color{brown}{ 2}}\\ &3(2)^{{\color{brown}{ 2}}}\\ &2(3)^{{\color{brown}{ 2}}} \end{array}\)

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1so what ybarrap said at the top, you plug in each x coordinate into each function and see if you get the correct corresponding y coordinates Let's say we pick choice B at random \[\Large f(x) = 2(3)^x\] The first point is (1,6). To test if this point lies on the function f(x) curve, we plug in x = 1 and see if y = 6 pops out \[\Large f(x) = 2(3)^x\] \[\Large f(1) = 2(3)^1\] \[\Large f(1) = 2(3)\] \[\Large f(1) = 6\] It does, so (1,6) is definitely on this curve. How about (2,12)? Let's check \[\Large f(x) = 2(3)^x\] \[\Large f(2) = 2(3)^2\] \[\Large f(2) = 2(9)\] \[\Large f(2) = 18\] Nope. The point (2,18) actually lies on this function curve and NOT (2,12). So we can rule out choice B.

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1So what just happened was that I've proven that the function \(\Large f(x) = 2(3)^x\) does NOT go through both points (1,6) and (2,12).

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0okay, so its A, C, or D lol.... so lets try to rule out A...

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1what did you get so far in checking choice A?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0that A is, in fact NOT the answer!?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1if x = 1, then what is f(1) ?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Wait, so it IS A!!!!!

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1\[\Large f(x) = 3(2)^x\] \[\Large f(1) = 3(2)^1\] \[\Large f(1) = \underline{ \ \ \ \ \ \ \ } \text{ (fill in the blank)}\]

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1and how about f(2)

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.1Good. Choice A is definitely the answer. As practice, why not go through C and D and eliminate them. With choice C, if x = 1, then what is f(x) equal to?
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