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My math test..Heres one of the questions


Laz.e.rus

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(edited)

x1 = -0.333333333333333333333333333333333333333333333333333333333333333333333333333333

333333333333333333333...

you get the picture? :)

x2 = 2.4

I think they mean valueS, no?

 

 

Edit:

x1: the slope is just 3, and you start at -2 for the y value, so it's 2/3 to the right of -1 (or what I did was 1/3 to the left of 0) to get -1/3 or -0.3 repeating.

x2: slope 1/5, so it's 3/5 to the left of 3, which is 3 - 3/5 = 12/5 = 2 2/5 = 2.4

Edited by DarkArchon
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(edited)

LOL!!!!!!!!

 

Hmmm, 4, 2, 2, or 1 eh? I guess you have a 30% chance of getting it right, assuming one of the answers is correct :P

If I HAD to pick one, I'd guess they meant g'(x) and I'd pick 1. :shrug03:

Edited by DarkArchon
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If it makes you feel any better, for my numerical methods exam we had a 4x4 matrix A, and a 4x1 vector b such that Ax=b. We were told to find a 3x1 vector, x. Unfortunately it was a fill-in-the-blank and there were indeed only 3 spaces... I considered just writing my prof a note saying it's impossible, but I opted to just write an extra blank and get marks.

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1 because y = g(x) = 0 so your looking for when the graph crosses the y axis hence 1 is your answer

 

Close...

If the question was find g(0) you would be correct.

But Y= g(x) = 0 so, Y=0. You need to find X where it crosses the Y axis of 0.

If Y=0, there are only two points touching it.

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heh - we had 3 messed up questions on this test of 20 total

 

Another was f(x) = (some linear variable). Find f(1)

 

I answered correcty, f(1)= -13

 

It was marked wrong cuz in the auto answer it said f(-4)= -13

(It didnt ask for -4, It asked for 1)

 

And on another you get variables for 2 functions (f and g), then are asked for (fg)(0).

We never encounter that type of notation, only (f x g)(0) or (f o g)(0) so I didnt know if it wanted a product or a composition. I guessed and gave the product and got it right.

It was just messed up that a format not covered in the class at all was used.

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Demoner, actually when y = 0 is when it crosses the x-axis...

 

So which one did you pick?

i meant x axis, my bad, why is it 1, 2, 2, or 4? is the multiply suppose to be the # of times it is 0??

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I left it blank and emailed the teacher with the two correct answers. Then I posted in the class discussion area that the test was brokeded and that Id email the details instead of posting cuz the test was still up.

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Demoner, actually when y = 0 is when it crosses the x-axis...

 

So which one did you pick?

i meant x axis, my bad, why is it 1, 2, 2, or 4? is the multiply suppose to be the # of times it is 0??

 

Either the question was asked incorrectly, or something.

Supposedly the correct answer was 1, but that only works if the question had been to find the function g(0) not

if youre supposed to find the value(s) of x when g(x)=0

 

Its not multiplying (although it looks like it!). Its labling a function.

In this case its saying that the y axis is 0 because the function g(x)=0, so if y=0, what is x there? ie: where does the line cross the y axis of 0?

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(edited)

Ooo I never thought of the number of times Demoner.

 

OR maybe the axes are labeled wrong???

 

Yeah, sounds like a great test there Laz. Sounds like it needs some work :) though maybe you guys were the trial run?

I honestly believe that if a question doesn't make sense it should be an automatic free mark. I'm going to do that with my students when I teach for sure.

Edited by DarkArchon
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well, #3 could have been a typo.

But #5 is a mess cuz people will answer 1 like you did and thats wrong, but they wont know it. Might mess em up good.

And for #20, I just dont think its cool to throw stuff in if its NEVER been in the class.

Maybe its teacher humor or something :)

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well, #3 could have been a typo.

But #5 is a mess cuz people will answer 1 like you did and thats wrong, but they wont know it. Might mess em up good.

And for #20, I just dont think its cool to throw stuff in if its NEVER been in the class.

Maybe its teacher humor or something :)

i've had many professors who've thrown loop ball questions on the test never covered. i think just to test us to see if you read the material, and just to tinkle off their students

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isnt it 1? it would be two points if the equation read x = g(y)

 

just guessin, i never ran into 2 many typos in my previous math classes, but i suppose thats a bad statistic to judge this situation on...

 

either way, i will be checking back when the answer is known :D

 

 

:spin2:

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Just backwards. It's g(x)=0, and y=g(x) like Laz said. So it's when y=0 (ie when it crosses the x-axis), and it does that 2 times: -0.333 and 2.4

Now if it read x=g(y), g(y)=0, then yeah. But then again you could leave the equation how it is and just swap the x and y labels on the graph to get the same effect.

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