anonymous one year ago Will Fan and Medal!!! Just need someone to check these for me!!!!

1. anonymous

2. anonymous

@Nnesha @pooja195 @ganeshie8 can any of you help me please

3. whpalmer4

No, the first one is not correct, didn't check the rest.

4. anonymous

ok then would the first one be a?

5. whpalmer4

One check you can do yourself for checking inverse functions is to plot a few points of the original function and a few of the inverse. The inverse function will be an exact replica of the original reflected across the line $$y = x$$ (just a line extending up and to the right at a $$45^\circ$$ angle). I have plotted your answer here so you can see that it is not correct:

6. whpalmer4

Here's what it would look like if correct:

7. whpalmer4

No, (a) is not correct either. Can you show me how you are doing this?

8. anonymous

ok what did u use to get that? that can help me

9. anonymous

my teacher just told us that you would need to make everything opposite?

10. whpalmer4

Oh, it's an expensive program called Mathematica. There are undoubtedly many cheaper or free options, this just happens to be the one I have at hand. You could also use graph paper and pencil :-) Uh, that's probably not exactly how they put it... Let's say you want to find the inverse of $f(x)=3x+2$First, replace $$f(x)$$ with $$y$$: $y = 3x+2$now switch the two variables. anywhere you see $$y$$, you put $$x$$ and vice versa. $x = 3y+2$ now solve that for $$y$$ and you have your inverse function $x-2=3y$$y = \frac{x-2}{3}$

11. anonymous

soo i dont really know what to do she not a very good teacher

12. anonymous

wow ok i understand now thanks can u check the rest imma try to solve it real quick

13. whpalmer4

ok, I'll the check the others and you do that one

14. anonymous

would it be umm d?

15. anonymous

1+x/4=y is what i got but it can also be the same thing as d right?

16. anonymous

|dw:1443542618922:dw|

17. whpalmer4

ah, yes, that's better. you need to write that as $(1+x)/4 = y$if you are going to write it all on one line like that

18. whpalmer4

by the rules of operator precedence, $1+x/4 = y$ is the same as$1 + \frac{x}{4} = y$

19. whpalmer4

So yes, (d) is the correct answer for the first part. Unfortunately, you probably realize that you did 2 of the others incorrectly...but got the 3rd one right.

20. whpalmer4

(to be clear, 3rd one is referring to Question #3)

21. anonymous

yeah i realized that can i solve them and u check them for me real quick? yeah i know what u meant

22. anonymous

#1. D #2. idk how to do that one? #3. D #4. C Are they correct now and can you help me on question 2?

23. anonymous

@whpalmer4

24. whpalmer4

Ok, for 2, we have to first find the inverse function, then evaluate it at $$x=9$$ What is the inverse function of $$y = 6x-3$$

25. whpalmer4

sorry, I looked too quickly at your answer for #3, that's not correct...but we'll work through it and get the right one.

26. whpalmer4

@Zbratz7 you home?

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