You should be able to solve this.
>>752607045
You dont know me or what I 'should be able' to do.
>>752607045
EZ PZ if you use integrals
/thread
>>752607045
thought it was quite easy but then I saw the bottom left segment is white
no idea lad, I haven't done any maths since really easy, basically A-level shit in undergrad
there is not enough information provided to solve the problem
so I can solve this one ;)
>>752607045
Maybe if i had my math notes and 10 min of spare time Anon.
bump
Dont blame the pupils. Blame the governmenet for the schoolsystem in many countrys especially in north America. I heard its really fucked up in some regions.
>>752607238
thers' anoter (intelligent) whay?
>>752607238
Do it then newfriend
Is it 21.46?
>tfw sucked at math in school and still do
i could, but it would be a pain in the ass
>>752607748
not because of picattached
>>752607772
Then stfu.
>>752607748
If the lower left cornor was filled out then yes. Since it is not, you have to do actual maths. Nothing too hard, but hard enough that i don't want to waste time on it.
10 x 20 = 200
π x 52 ≈ 78.54
78.52 : 2 ≈ 39.27
dunno about that white corner to the left
>>752607843
>just realized I didn't even think of taking out the corner
Brainlet feels
>>752607879
no u
Red Area (Ra) = Triangle Area (Ta) - Circle Area (Ca)
Ta = 20 • 10 • ½ = 100 a.u
Ca = 52 • π = 25π
Ra = Ta - Ca
Ra = 100 - 25 • 3,14
Ra = 100 - 78,5 = 21,5 u.a
That's how I solved it
Find half of rectangle area.
Subtragt circle area.
Then you just have to find a way of figuring out the missing spot. No idea about how you do that.
>>752608118
lower left corner little brainlet
>>752608213
2+2=4-1=3 quick mefs
>>752607045
Red area = Triangle Area - 1 Circle Area - (10 Square Area - Circle Area ) / 4
>>752608118
good try Anon
You're missing that small area tho
>>752607045
Approximately 19. Kinda dumb how the area in the bottom left was left unshaded.
>>752608360
Nice try. But look again
>>752607045
its 20
>>752608286
I missed a /2 on everithing!
>>752608286
Best try so far, but this is also wrong.
Note that the answer must be a bit under 4(200-50π)/8
>>752608597
Still too big.
About the little white corner:
We can take half of the figure and make a square. So we have:
4 Little Corners (Lc) = Square Area (Sa) - Circle Area (Ca)
4Lc = 100 - 78,5
4Lc = 21,5
Lc = 21,5 • ¼
Lc = 5,375
Now that we've found tha missing corner, we just take it away from the total.
21,5 - 5,375 = 18,125
ANSWER: The area of the red region is 18,125 a.u
i don't know but i assume the answer is somewhere around 10
>>752608806
Too low and not rigorous. But it looks like you have the basic idea of a Riemann sum floating around in your head somewhere.
>>752608786
I am dumbfounded by the fact that you guys can make the same mistake 5 times in a row.
LOOK AGAIN
>>752608687
>4(200-50π)/8
>4(200-50π)/8
My solution >>752608687 is 19,50
>>752607045
100-95×pi nigger ?
>>752608957
Damn!
>4(200-50π)/8
>Still too big.
My solution (>>752608597) is 19,50
>> 752608786 #
Wut?
>>752607045
AB=((10^2+20^2)^(1/2))/2=5*5^(1/2)
AC=((AB)^2-(10/2)^2)^(1/2)=10
R=AC/2=5
Sc=π*R^2=25π
S=(10*20-2*Sc)/2≈21.4602
>>752609034
I...
I can't even...
>>752609191
What ?
>>752609052
>19,50
Closest so far. Now give me a closed form.
Hey guys, can help me real quick? How do I answer someone? Like, directly to another anon?
>yfw people don't fail so much at the math but fail at looking at a fucking picture
just use πr^2 with 5 as your radius
times this by two, as we have two circles, giving around 157.08
200 (the area of the rectangle) minus 157.08 gives 42.92
divide by two for 21.46, the shaded region
>>752609155
nigger did you just use the pythagorean theorem to find out the circles radius is 5? how stupid are you that you can't divine that instantly from the picture?
>>752609382
THANK YOU SO MUCH! HAHAH
>>752609240
Yust put a 2 under >>752608286
The first integral is 1, but I can only approximate the second one.
>>752609270
>Hey guys, can help me real quick? How do I answer someone? Like, directly to another anon?
>>752609034
Negative area?
you fools, the rectangle has a third dimension
>>752609489
>but I can only approximate the second one.
Looks like you're boned then.
>>752609464
Now select part of the text in a post before clicking the postnumber. Prove you tried by quoting this post.
15
>>752607045
Intersecting line is y = x/2. Circle is diameter of 10, you can use that information to plot the circumference of a quarter of the circle as a line. The area under the line (integral) created by their intersection (y = min(both functions)) is the area of the not red bottom left zone. You could do some flips and calculate the top right red zone by itself if you wanted to instead. Probably easier that way since you can just add that to 0.75 * (100 - pi * 25) for the answer.
I dun wanna do the integrals because I don't want to turn my brain on, so you can just have the logic for the correct answer instead.
>>752607045
I got 175-π225/4
It's around 21.5
Its really not that hard
20 * 10 / 2
-
1 whole circle
-
that little bit I can't calculate bottom left
gg
>>752609532
AB and CD immediately prevent one another so yeah ok
>>752609570
I'm an engineer anon, I don't need closed forms. ;)
I will monitor this thread for the exact solution.
>>752609677
that's a negative number my guy
>>752609583
>Now select part of the text in a post before clicking the postnumber. Prove you tried by quoting this post.
Did it, i guess
>>752607238
This. Without calculus, it's actually pretty cumbersome.
All of the area that's not a white region.
21,46?????
>>752609583
>Now select part of the text in a post before clicking the postnumber. Prove you tried by quoting this post.
Did it, I guess hah
>>752609744
>I don't need closed forms.
Then get out of my class. TBH, you did good though.
>>752609532
there i even made it harder
100 (half the area of the rectangle) - pi r ^2 where r is 5 (half of the height of the rectangle)
>>752609743
Lines do not need to be straight
>>752609834
is that right?
>>752607045
68.6?
>>752608932
What is wrong, man?
>>752609532
too ez, gimme another one
>>752607728
>This
pretty sure u can do this with basic geometry and trig, dont have time to try it atm tho.
>>752609532
2 lines is enough
Easy.
Find the area of the rectangle which is 10×20 so 200, then we can assume that the diameter of the circle is 5 each since they take half of the rectangle each. Then we can do py × r (2.5) squared which is 19.6 . Then we can do 200-19.6-19.6 since their are two circles. That would leave you with 160.8. . We can divide that by 6 since there is 6 segments that arent cricles. That would be 26.8. Then since there is three red segments we'd do 26.8 × 3 = 80.4.
Solved.
The answer is 80.4 (whatever measure) squared
>>752608786
Not OP, but this is right. Area of triangle minus area of circle minus one of the small corners. 100-78.5-2.6875=18.81
To be honest I'm only here for the Kurisu pics
18,7775????????
Am a maths noob, don't know if this makes sense but:
Area of triangle-circle area=100-25(pi)=21.46. So area of bottom right corner red is 21.46/4=5.365.
use tan(x)=o/a to get top right angle 63.435. As a fraction of 90 degrees the red area (bullshit potentially imminent here) is (63.435/90)x5.365=3.781.
If that's true, then total red area is (3x5.365)+3.781=19.876.
As stated, I don't know what I'm fucking doing.
>19.67
Because 20 is double 10.
>>752610351
You didn't use three lines, therefore it's wrong anon. IT"S ABOUT THE METHOD NOT THE ANSWER. I don't care if you can do every derivative in your head, you need to write down the stupid long way formula or you don't get points!
>>752610351
>>752610425
Way off. The way that the hypotenuse bisects the circle allows you to take the area of one circle and subtract it from the area of the triangle. Also, you calculated the area of a circle like a dipshit. 2.5 is not the radius
>>752607759
as you say
>>752610625
Fine, here it is with 3 lines.
>>752608923
better?
>>752610512
Dank.
how to calc area of one of the small circle segments, thats all i need to solve
>>752610297
LOL!
I'm curious to see anon's answers
>>752610836
The figure never said it wasnt drawn to scale, because of this we can assume since there are two identical circles in a 10cm rectangle that the diamter of each would be 5, making the radius 2.
>>752607045
Found the lower triangle. (10*20/2)
Then found the circles 3.14 *5^2
Then sub circles from triangle
Divide sum by 5
Multiply by 4
>>752607045
(big rectangle - 2 circles)/2 = (200-50π)/2 ===> A
divide big rectangle into 4 small rectangles
(small rectangle - half circle)/2 = (50 -12.5π)/2 = small lower left bit ===> B
A - B = (200-50π)/2 - (50 -12.5π)/2
=16.09513775
>>752610896
fuck, das wrong. Fixed
>>752610297
25%, twice. So 50%.
>>752611018
You're getting close, but this will not yield a closed form unless you can do some nasty limits. On the right track, conceptually though.
>>752609362
>this
100-25(pi)
>>752611054
C
cus the right answer ain't there nigga
>>752611018
Great except your grid is wrong, that's clearly over 12 for one side and not 10...
>>752611249
Nvm, I missed the white bit in the bottom left ;/
>>752609532
Come one guys, this is easy.
https://www.youtube.com/watch?v=xnE_sO7PbBs
>>752607045
this is what I came up with, it's still unfinished
any help?
>TFW OP needs help with homework
>>752611103
This is incorrect.
>>752611481
>TFW OP needs help with homework
You wish, m8.
>>752609677
>>752609777
>dubz begets trips
>>752611363
12.5 small blocks = 10 cm
>>752611519
I think it's time to post the solution, we're obviously incapable.
>>752611465
HE DID IT
>>752607045
19,8765978902436 calculated with excel:
in big overview not to make it tldr:
(20*10)/2 half rectangle area - pi*5^2 half circles area gives 21,4601836602552
this lower left corner is 1/8th of this roundy shaped wedges, but also take a notice that you need to divide it somehow, so i just measured diagonal line inclination angle from atan 10/20, it measured 26,565051177078 degrees, so from proportion i made 26/90*1/8th sum of the corners and wedges amount
>>752611656
I'll post in a bit.
>>752611519
oh ffs right i didnt multiply that part by 3
>>752611681
That's rude anon, just because i was born a boy doesn't mean i'm not a girl.
>>752607045
21.460*0.916=19.657
easy
>>752611724
This is still incorrect. Any rational multiple of your solution will be incorrect because one of the transcendental numbers in your solution is wrong.
>>752611078
you are either trolling, or a nigger
there is a single circle in a 10x10 square, making its diameter 10 and its radius 5
>>752611608
Then you shouldn't count the squares, retard.
>>752611923
did you really take this long to figure that out?
>>752607045
Is this Seto Kaiba as trap?
>>752611711
Is >>752610570 correct?
>>752612028
No.
Create a Rectangular Coordinates,then use analytic geometry.problem solved
>>752611990
that was my 1st post
>>752607045
1/2(200-2*pi*5^2)=
100-25*pi
>>752611926
whatever floats your goat
>>752607045
Diameter: 5
Area: 25π
Area: 200
(200 - 50π) / 2 = 21.46...
About 21.5 units
OP here, the solution is 90-125π/4+25arcsin(2/√(5)). Many valiant attempts were made.
>>752612213
Except it isn't half of the cropped out corner it's 1/3 of it.
>>752607045
I don't know what red is
>>752607728
Blame the parents (mostly black single mothers) for how dumbed-down US schools have become. If the schools kept standards at pre-1970 levels, no black kids would ever graduate.
20,99
>>752612282
So 19.5
>>752607045
>red regions
>red
fuck off commie
>>752612407
No, silly.
>>752607206
pussy
>>752612542
But 19.5, honestly though...
>>752612806
> thinks and arbitrary number of digits can actually represent an irrational number
incorrect
Heuristical approach, this thread would be dead when I would finish with integrals
>>752612806
The structure of the real numbers is far to rich to be captured by approximations from rationals to any degree. Truncating 90-125π/4+25arcsin(2/√(5)) to any precision loses properties of the value. For instance 90-125π/4+25arcsin(2/√(5)) is irrational, but any decimal approximation is rational. Such truncations are useful in numerical analysis, engineer, and physics, but this is pure math.
The main thing to take away here is that numbers are not just defined by what rationals they are close to, they are defined by what properties they satisfy. If I tell you it's 90-125π/4+25arcsin(2/√(5)) you can get any precision you want from it if you're so inclined to get its decimal representation, on the other hand if I give you the first few digits of an approximation to it you will not be able to find the next one. The only reason you have that many digits of the answer is because I gave you the closed form.
>>752607045
40.
niggardly
>>752607045
No, the people I employ should be able to solve that. Stupid wage slave.
So this one is actually solvable, and fairly easy at that. None of that shit where there's simply not enough information.
Red area is ~ 19.505
Solution can be done with year 12 level mathematics (talking from a German maths teacher perspective), but solving the antiderivative without the use of a calculator will be beyond most pupils.
I know that some of my students visit /b/. So, if you can recognize my hand writing, have a nice weekend. Like I didn't say that to you 6 hours ago :P
>>752613405
You can't recognize your trigonometric substitutions. This is sad.
>>752607045
Well if we're measuring in miles, than its the same mass as your mom's ass: a lot
>>752612090
This made me laugh harder than it should have.
>>752613515
well, here's the upside: my solution needs a calculator only once, for arcsin(3/5)
https://mindyourdecisions.com/blog/2016/08/07/can-you-solve-this-geometry-problem-for-6th-graders-in-china/
>>752613515
how bout you present your solution instead of shitting on a contribution thats actually helpful
>>752613405
if you are a teacher, you should write with a proper cursive handwriting, not like a 10 years old kid
>>752613901
stay classy, /b/
>>752613824
No. Recognizing the required trig sub is trivial, if he can get that far and not see it, or look it up then I won't do it for him.
>>752613405
LEARN TO WRITE
>>752607045
Shaded Area = 17.91
>>752613405
>19.505
Nope, the third decimal is less than 5.
Here's an even harder one for you faggots.
>>752616271
19,504?
>>752607045
>find erea of rectangle
>diameter of circles is 10 obviously
>use pi to find erea of the circles
>find the diagonal of rectangle for hypopotenuse
>find erea of that triangle
>subtract the erea of the circles
>>752616838
Nope.
>>752616683
(5*365*24*60)/72*15=547500
am I missing smth?
>>752617599
https://en.wikipedia.org/wiki/Auschwitz_concentration_camp
>>752607843
About 20%
>>752617827
True statement, but not the answer.
yep i should be able to
>>752618097
You didn't even fill the right section and that won't yield a closed form.
>>752618204
right, im retarded and didn't see that missing section, this should be correct.
>>752618338
>this should be correct.
It's not correct.
Work out area of rectangle. Subtract area of 1.5 circles with a radius equal to 5. subtract 10x5 units. Divide everything by two.
>>752618338
>in^2
>>752607045
Sage
>>752618407
rounded.
>>752619090
I don't want it rounded. Give a closed form.
>>752619052
OP is quite anal about these threads.
"Hurr durr not closed form".
>>752619122
I also don't want it in the butt.
That is where we differ, op, right? Right.
>>752619279
>>752619310
You guys really don't get it, 90-125π/4+25arcsin(2/√(5)) is a number, it is the answer. No need to round it or make a decimal approximation for it.
>>752609532
nowhere does it say you can't think outside of the box
>>752617599
You are missing a couple of days within that 5 year span
It is possible to have 1 or 2 leap years within that time space so it would actually be either:
548,100 or
547,800
>>752607238
I can do this shit with just areas
>>752607045
You have a fundamental flaw in your logic.
This thread will only attract people who can't.
>>752611112
then what?
>You should be able to solve this.
Maybe, but who gives a shit. I'll never use any of this IRL.
>>752622733
This is real life.
>>752622999 (Fukken Checked)
You know what I mean, you butthole.
>>752611112
this one gave my brain a circular reference...
What level of math is this? I can't even figure out the first step
>>752623838
It's integral calculus, something undergrad stem majors cover.
19.50398599
Next
>>752607436
>thought it was quite easy but then I saw the bottom left segment is white
Same. If it was red, the answer would be 100-25pi.
>>752624371
Enjoy >>752611019, >>752610281
>>752624471
Meant to quote >>752624233 but eh.
>>752624233
Right answer and dubs what a great day
>>752611059
Underrated
>>752624652
op's been over why it's wrong dude
Lower left corner is the square-circle divided by 4
>>752624790
Its not wrong.
>>752624948
It is incorrect, and I'm no longer going to pursue it.
>>752607045
subtract area of circles from total area, divide that by two, and then subtract out the small area in the bottom left, which i'm pretty sure can be found with integration. you can set the circle equation equal to the equation for the line to find the point where they intersect.
Wow a post with some critical thinking on /b/
Off-note I suck balls at anything related to math and geometry
I'm better at abstract thinking and social sciences.
>>752625091
No it's not lol. This is the exact area.
>>752625126
Mathematics requires a heavy amount of abstract thought; it just requires a good amount of studying.
