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/sci/ - Science & Math

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4573795 No.4573795 [Reply] [Original]

Math retard here

I can't figure this out for the life of me. I'm probably making a stupid mistake somewhere. Can /sci/ help me out?

>> No.4573802

Plot the function being integrated for x<0.9 and x>0.9. You'll notice that you can split the integration up into two simpler integrals.

>> No.4573803

A Goofy Movie is fantastic

>> No.4573807

>>4573795

draw the triangular region enclosed by abs(10x-9) , that is a line with slope 10 and y intercept of -9, but reflect all the negative parts of the graph in the x axis, since it's absolute value. Then find the area enclosed from x=0 to x=1.

>> No.4573806

>>4573803
dat Roxanne

>> No.4573815

>You have attempted this problem 9 times.
>Your overall recorded score is 0%.

>> No.4573818

dude, you don't need to do it the way they tell you to do it, especially since there is no way to submit a picture or your work.

the answer is 4.

>> No.4573820

>>4573818

My first attempt was 4 which is apparently wrong. I know that area is a retarded way to evaluate an interval, but I can't seem to figure it out through simple calculations.

How can I calculate this integral using antiderivatives?

>> No.4573825

>>4573820

Fundamental Theorem?

>> No.4573832

>>4573820
my bad, it's 4.5

the y intercept is -9, and you are only going from 0 to 1 on the x axis.

it's a triangle with height 9 and base 1, so the area will be 4.5.

>> No.4573833

call the cops i dont give a fuck

plug in your x's

>> No.4573835

>>4573832
This nigga

>> No.4573836
File: 37 KB, 1562x768, chickenscratch.png [View same] [iqdb] [saucenao] [google]
4573836

>>4573833

forgotpic

>> No.4573837

>>4573836

forgot to make it 9x, not 9.

u get teh point

>> No.4573839

>>4573832

The answer is not 4.5

>>4573825

Using the fundamental theorem, I somehow came up with 10. I seem to be looking over some mind-numbingly simple detail.

>> No.4573842

Are you retarded OP? Do what the instructions say and you are golden.

1. Go to wolfram alpha
2. type in |10x-9|
3. look at it
4. Find the area using triangles (hint, you need 2)
5.???
6. Fuck yourself with a rusty nail

>> No.4573845

all they're getting at is that absolute values make a V shape (or inverted V). if you look at it like a triangle, take <span class="math">A = \frac{1}{2}bh[/spoiler]

an easier method would be to just ask wolframalpha or a ti-89 for the answer.

>> No.4573849

>>4573839
shit nigger, i keep having brain farts.

it's 5. at x = 0 you have -9, at x = 1 you have 1. base 1, height 10, so area is 5.

>> No.4573853

>>4573849

It's not 5 either...

>> No.4573860

>>4573818
>>4573832
>>4573849
is this all the same guy?

>> No.4573863

Thanks /sci/, the answer was 4.1. I need help with 2 more so stand by.

>> No.4573868
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4573868

>>4573853
what nigger assignment is this? the line makes a fucking triangle of base 1 and height 10.

if it's not 5 then i don't know what the fuck it is.

>> No.4573870
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4573870

Here's the next one. Thanks to all that contributed to the last problem.

On a side note, it's not that I don't understand integrals. It's that the professor assigns the most fucktard simplistic forms in class while webwork has problems much more complicated.

>> No.4573872

maybe you guys should review a little
http://tutorial.math.lamar.edu/Classes/CalcI/ComputingDefiniteIntegrals.aspx
This guy knows whats up >>4573802

>> No.4573893

>>4573868

I know your frustration. It would be much easier to simply calculate it using the fundamental theorem, but webwork believes it's necessary to do this retarded setup to understand integrals.

>> No.4573898

>>4573893
What's there to understand using theser shitty triangles? That's retarded.
Would make more sense if you used the sum of the bars instead, tedious and boring as fuck but that says something about integrals.

>> No.4573911

>>4573870

any tips on how to accomplish the second problem?

>> No.4574118
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4574118

>>4573870

It's assholes like this who go on to be those engineers who can't write procedures or tie their own shoelaces.

>> No.4574136

>>4574118
As compared to aspie boy-lovers like you?

>> No.4574141

http://www.wolframalpha.com/input/?i=\int_0^1+|10x-9|+dx

>> No.4574143

>>4574136
oooh, watch out, we've got a tough guy here

>> No.4574158

There's a lot of junk in this thread, so hopefully I can answer things completely and concisely (and without any errors). Because this is an absolute value function and has a sharp corner in it, you'll need to split it up into 2 integrals. You'll know the limits of integration by solving for when Y = 0. Let's call that number "z" for now. Your first integral will go from 0 to z. The second integral will go from z to 1. You can now just solve and add the two areas. Got it?

>> No.4574162
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4574162

hey, someone do my homework too please huehuehue

>> No.4574174

http://www.wolframalpha.com/input/?i=integral_0%5E1+abs%2810x-9%29+dx
huuuur

>> No.4574178
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4574178

>>4573870
>those problems
>professor
>professor
>professor
idontwanttoliveonthisplanetanymore.png

>> No.4574212
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4574212

>>4574143

Looks like the NSA is looking to hire talent.

>> No.4574215

if i do your homework, will you pleasure me?

>> No.4574227

>>4573898
They want you to be able to relate a simple "area-of-triangles" problem to the more advanced "definite integral". You can really solve it however and I hate when profs want you to do it their way

>> No.4574244
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4574244

this

>> No.4574258

>>4574227
well duh. this aint burger king. you cant have it your way.

>> No.4574269

fucking troll profs

>> No.4574284
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4574284

>> No.4574293

>>4574284
People like you are the ones who promote more kids and "retards" infest /sci/

>> No.4574297

guys i am a fucking highschool kid,where do i learn deriative/integral? not khan pls

>> No.4574301

>>4574297

Get a fucking book.

>> No.4574305

>>4574178
I can't believe nobody else is adressing the point that this would have been shit-tier exercise on a highschooltest and your 'professor' gave you these..

>> No.4574312

>>4573870
Wow, I really don't understand that one.