#help-0

1 messages · Page 645 of 1

alpine sable
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frrr lmao

vagrant meteor
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why wud i need help

alpine sable
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some kid showing his desmos picture lmao

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so its 84 + 21= 105 m^2

young finch
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i think that trapezoid on the top right of that one pic is impossible too

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hypotenuse 11 one side is 10 and the other is 4

alpine sable
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yeah it is hahah

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its not, u literally split it into a triangle and square

young finch
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wait prolly not let me check

alpine sable
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like i just explained

young finch
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but i mean the triangle part might be impossible

alpine sable
#

@trim hull you should email/contact your teacher lmao, atleast 2 of the questions are impossible.

alpine sable
#

with a special case here since its a right angle, the hypotenuse cant be smaller than the other sides but in that example it is.

young finch
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i guess you can still get a value with the right equation thats all the teacher wants

alpine sable
#

its not drawn to scale obviously

young finch
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huh

alpine sable
#

the shapes in the problems are degenerate. You'd basically be guessing how the teacher wants you to solve it (which i assume is using 1/2(a+b)h)

young finch
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how its drawn doesnt matter

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the values of the sides dont add up

alpine sable
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try drawing a right angled triangle with 5 as the base, 4 as the height and 1 as the hypotenuse @alpine sable lmao

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oml just coz hypotenuse isn’t the longest value who cares, they just want the answer to the questions

young finch
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thats like saying bob bought 20 apples from a store that only had 10 and saying its because the drawing didnt have all the apples he bought

alpine sable
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nice idc

young finch
lethal ore
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@pure olive Got the solution?

young finch
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i dont like geometry it makes my head hurt

alpine sable
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look up circle theorems

young finch
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i went to homework help and it told me to look at math notes that said something about inscribed angles

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wait am i dumb

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40+63=103

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180-103=77

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so measure QSO is 77?

alpine sable
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where did you get 40 from?

young finch
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inscribed angle

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80/2=40

trim hull
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can u tell me when u guys are done

knotty oxide
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Is this correct?

young finch
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👍

knotty oxide
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Thanks

trim hull
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need help with non red

alpine sable
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bruh we just had a whole convo about it earlier

young finch
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the same one?

alpine sable
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scroll up

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its an impossible question. same with the one top right. I would email your teacher.

young finch
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its just the top right one but different values

trim hull
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i understand that

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but i can't find the base

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ik the height

young finch
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no its just the area dont bother with emailing your teacher being like "tWo QueStiOnS aRe TecHniCaLlY nOt PosSiBle sO i DiDnT dO thEm"

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base is 9

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b1+b2/2 *h

trim hull
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height is 12.5

young finch
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wait no

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height is 14

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average of the two bases find that then multiply with height

trim hull
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still wrong

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no im 12

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not 11

young finch
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huh

trim hull
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im on the non red one

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im on the one that is next to the red one

young finch
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oh

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7+12.5/2*9.7

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the red one should be 105 btw

trim hull
#

ik

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wrong

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its aprrellogram

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parrellogram

young finch
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shouldnt parallelograms have two sets of parallel sides

trim hull
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12.5 and 7

young finch
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thats one set

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wheres the other

trim hull
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9.7 and 10.3

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but the 10.3 is wrong

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so idk

wicked parcel
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Classify the function f(x)=7(0.5)ˣ

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pls

young finch
trim hull
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ik

young finch
trim hull
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she did this on purpose

wicked parcel
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🥲

vagrant jetty
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is this taken ?

young finch
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ok then just find the area of the triangle and area of the rectangle separately and add if that didnt work

trim hull
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yup

knotty oxide
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Need some help on this one

young finch
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sin(B)=8/17

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B=arcsin(8/17)

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@knotty oxide@trim hull

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you guys still need help?

trim hull
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yup

tight locust
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,calc arcsin(8/17)

ocean sealBOT
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The following error occured while calculating:
Error: Undefined function arcsin

tight locust
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,calc sin^-1(8/17)

ocean sealBOT
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The following error occured while calculating:
Error: Unexpected type of argument in function pow (expected: number or Complex or BigNumber or Fraction or Unit or Array or Matrix or string or boolean, actual: function, index: 0)

tight locust
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wow

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,calc asin(8/17)

ocean sealBOT
#

Result:

0.48995732625373
young finch
# trim hull yup

what do you need help with? I said either divide the shape into a triangle and rectangle, find the area of the individual shapes, then add them together or use the formula b1+b2/2*h

tight locust
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,calc 0.48995732625373*180/pi

ocean sealBOT
#

Result:

28.072486935853
willow bluff
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Can someone help me ?

young finch
# willow bluff

divide into two triangular prisms and the trapezoidal prism or whatever its called

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i meant rectangular prism not trapezoidal prism

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or you can just find the area of the trapezoid then multiply it by its depth

young finch
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b1+b2/2*h then multiply by depth

willow bluff
young finch
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b1 and b2 are the two bases of the trapezoid

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so 5+3/2

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4

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then multiply 4 by the height

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then by depth

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the height is 4

willow bluff
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What’s the depth. I’m at 16

young finch
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9

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$$(5+3/2*4)9$$ is probably the best representation for this

ocean sealBOT
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Arctic

young finch
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oh

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i dont know how to make it look like a fraction

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just imagine the 2 is under 5+3

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$$5frac2$$

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idk

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$$5frac/2$$

ionic jewel
ocean sealBOT
young finch
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that would be 9

willow bluff
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I have been hit with confusion

ionic jewel
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do you want me to add = 9

young finch
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dont worry its just formatting with this bot

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derivatives are not okie dokie for me

ionic jewel
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whats the question

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if you want to integrate the second one, split it into 3 integrals, then you can do each one itself easily

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,w integral from 1/2 to 3 of -2x/3+7/3-1/x dx

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perhaps some wrong arithmetic something but the idea looks rigjt

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or perhaps i misread your handwriting somewhere

ionic jewel
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you got it right @alpine sable

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all of your work is correct

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so hopefully you understand that?

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if you just copied it from Wolfram i can explain it

alpine sable
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Me too

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Spam here

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Hi5 bunny

ionic jewel
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that emote is in my frequently used now lmao

alpine sable
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Show what you have done so far

ionic jewel
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,rotate

ocean sealBOT
ionic jewel
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The last integral is from the +7/3 in your original integral

alpine sable
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Last one is from the 7/3

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1 times 7/3 is 7/3

ionic jewel
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it's $\int_{0.5}^3 \frac73 , dx$ but they pulled the 7/3 out

ocean sealBOT
alpine sable
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The 1 is redunant

ionic jewel
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you should write it how I just did

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here let me put it in order too]

alpine sable
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$\frac73 \int_{0.5}^3 dx$

ionic jewel
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$$\int_{\frac12}^{3} -\frac{2}{3}x , dx + \int_{\frac12}^{3} \frac{7}{3} , dx + \int_{\frac12}^{3} -\frac{1}{x} , dx$$

ocean sealBOT
ionic jewel
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this is what its actually splitting into ^

ocean sealBOT
ionic jewel
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then wolfram is doing extra work to put it into a different form

alpine sable
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First one polska

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Yes

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First, put all constants in front of integrals so you can see better

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For example, you have integral -1/x dx Write it as minus integral of 1/x dx

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Then you can try and find the exact integral in the table

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Do the same for others too

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2/3 is a constant as well

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So is 7/3

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Do that too

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Then we can look at the table

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Looks good

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Now look for the first integral in your table

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Yes

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No, the integral is gone

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You will add them

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After you write it out, $-\frac23 \frac12 x^2 |$

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No

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@ionic jewel how do I do line

ocean sealBOT
alpine sable
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Almost

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Let me grab some paper and a pen, one moment

ionic jewel
ocean sealBOT
alpine sable
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The integral is gone, but you leave the limits like that

ionic jewel
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might just be able to do $\frac12\left|_a^b$

alpine sable
#

You dont need c for each, they all are a constant and constants add up to one constant

ocean sealBOT
#

bunny
Compile Error! Click the errors reaction for more information.
(You may edit your message to recompile.)

ionic jewel
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nah thats pretty ugly

alpine sable
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I wont remember that, but thank you

ionic jewel
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$\left. \frac12 \right\rvert_a^b$ should automatically scale

ocean sealBOT
alpine sable
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@alpine sable yes

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Even better, cancel out the 2's then multiply

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Yes

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Yep

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Now, the way you deal with bounds is you sub in the top bound and subtract the subbed in lower bound

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Waiting

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$-\frac13 [(3)^2-\big(\frac12\big)^2]$

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This

ocean sealBOT
alpine sable
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Your first was x^2

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So you sub in 3^2 minus (1/2)^2

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Instead of x

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Top instead of x minus bottom instead of x

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Yes

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And subtract top from bottom

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Yep

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Yes, and 7/3 in front

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One problem, should be minus ln

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Second problem, -(ln3 - ln(1/2))

ocean sealBOT
hybrid radish
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is anyone able to help with this?

alpine sable
#

have you learned about sin?

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Is that power of 3 or just 3

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Ln(x) is a function as a whole. It's not ln times x

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That's fine then

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Work out the mixed numbers and fractions

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Yep

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So you can multiply -1/3 and 35/4

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Same foe the second one

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For ln you have the rule: ln(a)-ln(b)=ln(a/b)

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Yes

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That's the same solution as wolfram

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End result

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Nope, the c stays

ionic jewel
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there shouldn't be a C

alpine sable
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Oh yeah, its a definite integral

ionic jewel
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this is a definite integral

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no C

alpine sable
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The c goes away

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need help with these 2 if thats ok

ionic jewel
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there should be no C in the entire problem, although technically there is but it cancels out halfway

alpine sable
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You didnt need it at all with a definite integral

ionic jewel
alpine sable
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Dont blaspheme, you're welcome hi5

young finch
alpine sable
ionic jewel
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unused channel is a good idea

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unless this one is now open

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also I do not see an f in your problem

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it's a geometric sequence

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and I gave the common whatever u wanna call it

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i gave the common ratio

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i think only arithmetic sequences have a common difference

alpine sable
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ah

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im stuck on what the ratio is

dense snow
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so if i said something like Apples to Orange is 1:2, than I could also say Apples/Oranges=1/2

near pendant
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okay so

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am i able to ask the thing for 4th time if i still havent got answer

dense snow
wild hedge
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hi can anyone help me with this question, i tried using ASTC but i cant get the second answer.

tight locust
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find the 0s of the function in that interval

golden arch
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Is x ln(x) = x?

tight locust
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not in general

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there is a value which should make that statement true

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it is a conditional equation, not an identity

golden arch
#

But isn't it equal to the ln x**x?

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or does that only work for log?

tight locust
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xln(x) = ln(x^x)

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that is true

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but xln(x) does not equal x

golden arch
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But if it was a log it would be right?

tight locust
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wdym

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ln is a log

golden arch
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or am i just mixing up different rules 😅

tight locust
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this is called power to product rule of logarithms

golden arch
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yes i am oops

tight locust
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ln(a^b) = b * ln(a)

golden arch
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i forgot that it had to be e

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Instead of x

tight locust
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it doesn't even have to be ln, it works with any base

golden arch
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my bad

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Thanks!

tight locust
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eln(e) = e yes

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good job

alpine sable
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Can someone solve these for me real quick?

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153

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107

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Could you please explain b?

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wait its not 107

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108

oak chasm
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@alpine sable @alpine sable Please read the rules in #❓how-to-get-help. Just giving answers is not allowed here.

alpine sable
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💀😭

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sorry

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My bad...

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I’m just trying to understand how to solve b

alpine sable
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Yes

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so then you can substitute in 45 instead of Un right, since you know what it is now?

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Right...

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So now you have the equation $2n^2-5n+3=45$

ocean sealBOT
#

sxkura

alpine sable
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Any thoughts on what to do next?

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Ugh

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Subtract 3 from 45

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I get what ur thinking but then you would have $2n^2-5n=42$ and you can’t really solve that can you

ocean sealBOT
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sxkura

subtle mantle
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yes, yes you can, just subtract 42 from both sides

alpine sable
#

Have you learnt about quadratic equations?

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Honestly I don’t know shit and I’m in high school

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Instead of taking away 3, take away 45 so the equation is equal to 0, this way you get a quadratic equation which you can then solve

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tell me what u get now from doing what i just said

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4n - 8n

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no

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take away 45 from $2n^2-5n+3=45$

ocean sealBOT
#

sxkura

alpine sable
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Umm

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lets break it down

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2n^2 - 5n + 3

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what would happen to the right side when you do 45-45

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0

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what is 5+6

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correct

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and whatever you do to one side of an equation you do to the other

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so now what’s 3-45

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honestly I’m totally confused

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This is not the way I got told to do it

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-42

alpine sable
#

so now we’re left with $2n^2-5n-42=0$

ocean sealBOT
#

sxkura

alpine sable
#

We have a quadratic equation now and we have it equal to 0 which is what you need to solve it

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Have u learnt how to solve quadratic equations

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Nope

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What you would do next is you solve that equation that we have for n, to find out what n is

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watch that, it’s easier than explaining

subtle mantle
#

or just use the quadratic formula

alpine sable
#

yeah I have too much to learn for this exam

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I understood so far

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Hopefully my scientific calculator can do the rest

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Is this right sorry

alpine sable
#

nah I appreciate your help. My bad I haven’t studied for years to regret it now.

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Prob will be back for more

unreal depot
#

anyone down to help?

alpine sable
#

what are you struggling with to begin with?

wild talon
#

Uh heres the translation : a,b,c,p,q,s forms an arithmetic series where the difference between the integers is a constant not equal to 0.
Show that the system only has one unique solution.

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I know the answers are there but i'd like to know how to do the problem

drifting jacinth
#

Comme a,b,c,p,q,s forme une suite arithmétique, de raison k par exemple, tu peux remplacer a par nk, b par (n+1)k, c par (n+2)k ...

wild talon
drifting jacinth
#

I guess you just have to solve the system

wild talon
#

also, wouldnt a stay as a and b be replaced by a + k then a + 2k so on

drifting jacinth
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ah, true

alpine sable
#

can someone find me the answer

wild talon
#

1 percent

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pre sure

drifting jacinth
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the channel is taken right now

alpine sable
#

ok

wild talon
#

wait no

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i dont remember how to do those acc my b

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ok wait

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i had

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it simplfied

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to

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yd = a + 2d
3dx + 4dy = a + 5d

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where d is the difference

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then put them together and just got 3dy + 3dx = 3d

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so y + x = 1

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which is on the right track i guess

drifting jacinth
#

i have y + x = 1 too

wild talon
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since -1 and 2

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but idk where to go from there

drifting jacinth
#

have you tried to replace x by 1 - y in the previous equation ?

wild talon
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yeah

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in the 3dy + 3dx = 3d one it wouldnt work cuz thats just where we came from

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and if i took the

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yd = a + 2d
3dx + 4dy = a + 5d

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ones

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i would also have to solve for a

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which we dont know either

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ok wait im just going to try anyways

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i dont think it works

drifting jacinth
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it does

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you replace it in which one?

wild talon
#

both

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then shifted them over so they both = 0

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and put them together that way

drifting jacinth
#

well, give me a minute to look at your equations

trim hull
#

Can someone help with this last question

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It's a trapezoid

drifting jacinth
#

no, this channel is taken for now

wild talon
#

3dx + 4d - 4dx - a - 5d = d - dx - a - 2d

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i just end up with x = all values

drifting jacinth
#

do you agree that ax + (a+d)y = a + 2d ?

wild talon
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yep

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and xa + 3dx + ya + 4dy = a + 5d

drifting jacinth
#

if you replace x in this equation, you'll get y

wild talon
#

replace x?

drifting jacinth
#

x = 1-y

wild talon
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with x = 1-y

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ok

#

a(1-y) + ay + dy = a + 2d

a -ay + ay + dy = a + 2d

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dy = d2

drifting jacinth
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x = 1-y, not y-1

wild talon
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oh crap

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bet

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thanks so much

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🙏

drifting jacinth
#

you're welcome

alpine sable
#

min at x = 1.53 & y = 3.07

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but why is my answer wrong?

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can someone help with this

trim hull
#

Hole server is thrash noone responds

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Trash

ionic jewel
trim hull
#

Welp

ionic jewel
#

the equation is going to be something like a_n = initial_value + common difference * n

tight locust
#

Arithmetic

ionic jewel
#

oops

dim epoch
#

is there any way to make a function from a vaalue table? I know you can do it with excel etc. but i need to know if there is a manual way

pallid void
#

A ball is thrown upward at an initial speed of 14.7 m/s. The height h in meters that the ball reaches t seconds after being thrown is given by the equation h=14.7t-4.9t^2. When will the ball be 9.8 meters high. how many seconds will the ball be in the air

dim epoch
#

barlow move to next channel

ionic jewel
#

if I had to guess I would think you may be looking for a least squares approximation

pallid void
#

@ionic jewel can you help me in #help-1 when you get a chance

idle trench
shrewd elbow
#

I need help with this I think I have everything right up to there but don’t understand how to continue

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<@&286206848099549185>

glass lichen
#

$2(x-5)^2=18$

ocean sealBOT
shrewd elbow
glass lichen
#

you cant take sqrt of both sides yet..

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unless you want to deal with unneeded radicals

shrewd elbow
glass lichen
#

square root

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but you havent isolated for just the a^2 yet

shrewd elbow
#

oh so i need to take away the 2 first

glass lichen
#

yes, you need to isolate the a^2 still

shrewd elbow
#

so now i have x^2 - 20x + 32 = -2

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is that right?

glass lichen
#

no

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cause you completely disregarded everything I said

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if you want to expand everything then sure, go ahead. Im trying to show you the quicker way given it's in vertex form..

shrewd elbow
#

wait would i take the 2x^2 to the other side and then divide by 2

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so now it would be 10x - 16 = x^2

glass lichen
#

Ok you're still heartset on expanding everything

shrewd elbow
#

idk what im supposed to do then

glass lichen
#

$2x^2-20x+32=0$ if you're insistent on doing it the long way

ocean sealBOT
glass lichen
#

$\implies x^2-10x+16=0$ which is factorable

ocean sealBOT
ionic jewel
#

why not just move the 2 and sqrt

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oh

#

i see the conversation

glass lichen
#

they want to do it this way 🙃

shrewd elbow
#

idk its just the way my teacher taught it

ionic jewel
#

i guess they get some bonus factoring practice

shrewd elbow
#

well atleast i know how to finish it now

#

ty

ionic jewel
#

it also works but its extra work for no reason

shrewd elbow
#

how can i do that tho

glass lichen
#

$2(x-5)^2=18 \ (x-5)^2=9 \ x-5=\pm 3 \ x=5\pm 3$

ocean sealBOT
shrewd elbow
#

oh i get it

ionic jewel
#

$$2(x-5)^2 = 18$$
Divide by 2
$$(x-5)^2 = 9$$
sqrt
$$x-5 = \pm 3$$
solve for x
$$x = 5 \pm 3$$

ocean sealBOT
shrewd elbow
#

my teacher never taught that

ionic jewel
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oh mosh is faster

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but do you not understand it?

shrewd elbow
#

i understand it now

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thank you thats so much easier

#

she never taught that

ionic jewel
#

$\frac2x = 5 \ 5x=2 \ x = \frac25$

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oh

ocean sealBOT
shrewd elbow
#

i have another question

ionic jewel
#

@glass lichen do u know how to do thicker newlines

shrewd elbow
#

whats the "completing the square" method

ionic jewel
#

that little trick doesnt work with fractions well

glass lichen
#

Nope

shrewd elbow
#

its the same thing as the last question but completing the square

ionic jewel
shrewd elbow
#

ok

glass lichen
ionic jewel
#

^

glass lichen
#

$y=ax^2+bx+c\to y=a(x-h)^2+k$

ocean sealBOT
alpine sable
#

is it possible to express these in exact form without the i?

shrewd elbow
#

only 7 more

oak chasm
#

@alpine sable Remove the i and put a negative sign inside the radical that i is next to.

charred flint
#

What is the millionth decimal digit of the 10^10^10^10th prime?

ocean sealBOT
#

Chai T. Rex

noble stone
#

here's what i did

opal hull
#

someone help me

#

pls

#

<@&681260374879633482>

trail stirrup
#

sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully sully v

opal hull
#

i need serious help

trail stirrup
#

yes you do

#

not in algebra

#

but in reading comprehension

opal hull
#

do you know what is

trail stirrup
#

read the rules

shrewd elbow
#

I have no clue how to do this ngl

#

I know how on a calculator but not algebraically

tepid flame
#

use discriminant i think

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D < 0

vital relic
#

^^

shrewd elbow
#

Isn’t discriminant formula -b/2a

vital relic
#

im mentally broken

tepid flame
#

no

#

no

vital relic
#

b^2 - 4ac

tepid flame
#

b^2 - 4ac

#

yeah

shrewd elbow
#

Oh ok ty

tepid flame
#

that is sum of roots

#

-b/2a

#

no problem sir 🙏

vital relic
#

its a problem sir 🙏

silver echo
#

-b/2a is x coord of vertex of a parabola

edgy owl
#

Um does anybody know how to find parallel lines in the slope by the equation?

silver echo
#

just same slope

vital relic
#

just if the slopes are the ame

#

y=2x + 1 is parallel to y = 2x

silver echo
#

^

shrewd elbow
#

Yesss only 5 more

edgy owl
#

How bout a negative

#

One with a negative and one without

vital relic
#

not negative

#

has to be the same

edgy owl
#

Ok

vital relic
edgy owl
#

How bout Y=2x +4 and Y= 4x +2

vital relic
#

just look at the coefficient of x

#

if its the same then parallel

#

in this case, the first coefficient is 2 and the second one is 4

#

so its not parallel

silver echo
#

try using desmos

vital relic
silver echo
#

you can input functions

#

should be very helpful

#

o.0

vital relic
#

good

edgy owl
#

How bout fractions? In the equation

alpine sable
#

ofc

silver echo
vital relic
#

dont respond to him, hes mentally damaged

#

good

alpine sable
#

0 = 0

alpine sable
vital relic
alpine sable
vital relic
sly mantle
#

@vital relic stop trolling @plucky gate stop shitposting

vital relic
#

okay

dim epoch
ionic jewel
#

are you trying to create a line that gets as close to all the points as possible

#

or are you trying to make a function that goes through some arbitrary amount of points

dapper karma
shrewd elbow
#

I have no clue what to do next

glass lichen
shrewd elbow
#

Yea

glass lichen
#

when it hits the ground, what's the height of the projectile?

shrewd elbow
#

0

glass lichen
#

so solve for t given that...

shrewd elbow
#

So 0 = to whatever

#

Or h = 0

glass lichen
#

I mean given we just established the height was 0

#

clearly h=0

edgy owl
#

What does it mean what is the equation of the line though the points?

vital relic
#

u have the points given and u just sub it into y = mx + b

#

so like say a line goes through (2, 3) x = 2 and y=3

#

so u get 3=m2 + b

edgy owl
#

2,3 and 4, 5 is y=x+1?

silver echo
#

@edgy owl

vital relic
#

^

edgy owl
#

Ok

patent tinsel
#

Hello please help wih this two >~<

alpine sable
# patent tinsel

remember the properties of a square, if TS=TR how would you write the equation if you have the whole of PR

patent tinsel
#

Uuum well like ST=PR? @_@

alpine sable
#

no because PR is the whole thing and ST is a little part you’re going have to multiply by 2 to equal it out

#

$$2(x+8) = 4x + 6$$

ocean sealBOT
#

karskaa

alpine sable
#

but given ST then it’s the equation i gave

patent tinsel
#

OoO then it's gonna be 2x+8=4x+6?

alpine sable
#

2x+16

patent tinsel
#

OoO oh yes

#

If i need to find QT too can i use their x?

alpine sable
#

why does this mean we assume x = y?

patent tinsel
#

OOOOO thank u!!!

tight locust
#

then you must assume that x = y

#

2x^2 = -1/2

#

x^2 = -1

#

hmm how do you solve that?

#

you have a negative number you have to take the square root of

#

i'm not sure that's possible

#

is it?

alpine sable
#

so we assume x = y, because there are still no solutions which doesnt change the problem?

#

but it makes the problem easier?

tight locust
#

yeah pretty much

rapid horizon
#

hey can someone help me with this i have a few questions btw

woeful stag
#

Think of each sector as part of a circle as AC and BC being radii of circles of different sizes

#

All you need to do is find the difference between the circle sector with radius BC and the circle sector with radius AC

#

and that's the shaded area

rapid horizon
#

yeah

#

so what is the formula that i need to use for everything

#

or formulas

woeful stag
#

well, what is the circle area formula, and how would you find the area of a 30 degree sector in a 360 degree circle?

rapid horizon
#

circle area formula is Area = pi(radius^2)

woeful stag
#

right, and how would you find a 30 degree sector of that circle

#

hint: use ratios

rapid horizon
#

sorry im confused by would it be pi on top of 180?

#

this channel is in use

woeful stag
#

ok, lets simplify things

#

what would the area of a semicircle be

#

what is a semicircle ?

rapid horizon
#

a semi circle is a part of a circle

#

like a circle cut off

#

but the area formula is

#

area = pir^2 /2 = pid^2/8

woeful stag
#

Just pi*r^2/2

#

A semicircle is actually a circle cut in half; by definition it is half of a circle

So if its half a circle, the area would be pi * r^2 / 2 (since it would have half the area)

#

which you seem to understand

#

But where does that 1/2 really come from?

#

Let's think

rapid horizon
#

yeah ik what a semi circle is

woeful stag
#

What is the angle of a semicircle at the centre?

rapid horizon
#

90 degrees

#

180 degrees

woeful stag
#

if this is our semicircle, what angle would it have

rapid horizon
#

ohhh 180

woeful stag
#

mods do ya thing

#

yeah, 180

#

So we know that a full circle have an angle value of....

rapid horizon
#

360

woeful stag
#

and so since a semicircle has an angle of 180 degrees, we see that the area will change based on how much its changed from the original circle right?

rapid horizon
#

yes

woeful stag
#

lets say 180 degrees = a, how can we use a in our formula pi*r^2 to find the area of the semi circle

rapid horizon
woeful stag
#

we'll make a generalization before we get to the solution

rapid horizon
#

ok

woeful stag
#

so that you can understand it better

rapid horizon
#

yeah alrighty

woeful stag
#

Think carefully, semi circles have 1/2 the area, and their angle value is 180 degrees, while the angle of a full circle is 360 degrees

rapid horizon
#

am i modifying that formula?

woeful stag
#

yep

#

you want to get something*pi*r^2

rapid horizon
#

180

woeful stag
#

to get the sector area

#

we saw before that the semi circle area = pi * r^2 / 2

rapid horizon
#

what formula is this?

woeful stag
#

semi circle

rapid horizon
#

area?

woeful stag
#

yeah

#

since its just 1/2 * Area of circle

rapid horizon
#

yes so do i have to add something to that

#

sorry just confused

woeful stag
#

let me say half circle from now on haha

rapid horizon
#

yeah ahaha

woeful stag
#

half circle will have half the area because its angle value over a full circles angle value will be 1/2

#

That is:
angle of half circle: 180 degrees
angle of full circle: 360 degrees

area = 180 / 360 * pi * r^2

rapid horizon
#

yes

woeful stag
#

which is also equal to?

rapid horizon
#

the area of a semicircle?

small hatch
#

How would this be solved? It's a review for my final in 5 days!

woeful stag
#

yeah! because 180/360 = 1/2

rapid horizon
#

mhm

woeful stag
#

So we can generalize this to any angle

#

since it will just be a ratio to a full circles angle value

#

which is 360 degrees

rapid horizon
#

yes, so then how would it be used in this context?

#

ohhhh

#

i get you

#

so for this im guessing

#

it will be

#

30 / 360 * pi * r^2

#

in this context

woeful stag
#

yes, exactly

#

A = angle/360 * pi * r^2

#

and there we've done it, we've described the circle sector area

rapid horizon
#

so then what else will be used in this context to find the "shaded area"

woeful stag
#

now we have two different radii right

rapid horizon
#

well what should i plug into the equation we came up with

#

here is the question again

woeful stag
#

since there's two different radius values

#

we see that one is larger than the other, and since the smaller circle sector is inside the larger circle sector, what can we do to find the area in between the two circles?

#

if I have a square with area 5 m^2 inside a square with area 10 m^2, how would I find the remaining area?

rapid horizon
supple socket
#

This problem requires strong induction

#

They assumed P(k) for all k that is less than n

rapid horizon
supple socket
#

I solved the problem the same way for all k that is less than or equal to n

rapid horizon
supple socket
#

sorry

woeful stag
#

how about this?

#

the red square has area 10

#

the blue square has area 5

#

how would i find the green area?

rapid horizon
#

multiplying the five again

#

or like

#

the inside peice

woeful stag
#

You would actually subtract

rapid horizon
#

oh the five

#

that area

woeful stag
#

Because the smaller square is part of the larger squares area right?

rapid horizon
#

yes

woeful stag
#

we know the difference would be the shaded area

#

the same idea applies to that circle question

rapid horizon
#

so what should i do now with the problem

woeful stag
#

the circle section with the smaller radius - lets call r1 - is inside the circle section with the larger radius, r1.

#

So A1 = area of smaller circle sector

#

= 30 / 360 * pi * (r1)^2

#

A2 = area of larger circle sector

#

= 30 / 360 * pi * (r2)^2

#

so the shaded area, as you may have guessed, would be the difference between which values?

rapid horizon
#

but which ones in the problem have a larger radius

#

uhh

#

the angle

woeful stag
#

Look at the diagram

#

BC is the large radius

rapid horizon
#

oh is it a and b

woeful stag
#

BC is the biggest radius, see the line between B and C?

rapid horizon
#

yes

woeful stag
#

and which would be the small radius? remember, the radius must touch the centre

rapid horizon
#

a and c

woeful stag
#

right, exactly

#

what values are given in the question for side lengths?

rapid horizon
#

well we obviously have the 30 degree angle

#

and then the distance of the shaded area is

#

3 inches

#

and the other part is 8 inches

woeful stag
#

right, so how can we describe that line

rapid horizon
#

the non shaded region

woeful stag
#

which line would be 3 inches? BC, AB, or AC?

rapid horizon
#

AB

woeful stag
#

right, and which line would be 8 inches?

rapid horizon
#

a and c

woeful stag
#

Okay, so we want BC first

#

since we said that it is the largest radius

#

But wait, it doesn't say what its equal to, how can we calculate BC?

rapid horizon
woeful stag
#

we need to find r2 first!

rapid horizon
#

so how we do that

woeful stag
#

how would we calculate the distance between b and c?

rapid horizon
#

add both the formulas

#

of AB and AC

woeful stag
#

Right, so BC = AB + AC

#

we said that AB = 3 inches

#

ac = 8 inches

#

so BC = ?

rapid horizon
#

is 11inches

woeful stag
#

right, exactly

#

and there we go, we have both the values we need

#

r1 = radius of small circle sector = AC = 8 inches

#

r2 = radius of large circle sector = AB = 11 inches

#

now we find the difference in the larger sector's area and the smaller sectors area and we get the ?

#

So A1 = area of smaller circle sector
= 30 / 360 * pi * (r1)^2

A2 = area of larger circle sector
= 30 / 360 * pi * (r2)^2

A2 - A1 = ?

rapid horizon
#

3?

#

wait now

#

no

#

sorry lemme do that

woeful stag
#

What would A2-A1 calculate?

rapid horizon
#

the shaded area in the whole model

#

or just in one

woeful stag
#

since its just 30 degrees we would only be calculating one right?

#

But in the question, it says that all four are the same!

rapid horizon
#

times it by 4

woeful stag
#

exactly

#

and there you go, that should do it!

rapid horizon
#

yeah let me calculate this

#

this was the hardest problem on the sheet i have a few more questions if you dont mind answering

woeful stag
#

sure! I'm going to leave in a bit though, so I'll try to help you out as simply as possible

rapid horizon
#

they are not as difficult as this one

#

did i set this up right?

woeful stag
#

yep! make sure to explain what A1 and A2 are!

rapid horizon
#

do i divide 30 by 360?

woeful stag
rapid horizon
#

also this is how you would describe A1 and A2 right

woeful stag
#

well, A2 would be A1 + the shaded area, the whole thing

#

which is why we use the long radius BC

rapid horizon
#

ok let me just do the other questions i only have like a few let me ask you these if you have to leave soon

#

this is one of them

woeful stag
#

just to make this clear:

rapid horizon
#

yeah i did that

woeful stag
#

awesome

#

this one is quite simple haha

rapid horizon
#

yeah i just gotta get it started lol

#

and i have a few that are very simple (2) and then one i gotta finish but i did the majority of work on

woeful stag
#

let s represent the arc length, and r represent the radius

#

then s = r*theta, where theta is the angle of the circle sector

#

just rearrange and solve for theta, not too much to include here 🙂

rapid horizon
#

wait so what

#

s=r*the angle but we dont have the angle

woeful stag
#

right, but we have s and r right?

#

ignore my ugly circle

#

i hope this gets the point across

rapid horizon
#

yes

#

we have the numbers on the graph

#

the radious of the rotation is 25

#

and the arc for ab is 58

woeful stag
#

right, so lets rearrange the formula

#

s = r*theta
theta = ?

#

(hint: its shown in the question)

rapid horizon
#

the arc?

woeful stag
#

if c = a*b , then c/b = a

#

if we divide b on both sides

#

similarly

#

s /r = r * angle / r
angle = s/r

#

r*angle/r = (r/r) * angle = 1 * angle = angle

rapid horizon
#

btw this is what i got for the last problem

rapid horizon
woeful stag
#

if s = r * angle, then dividing r on both sides, we can isolate the angle

rapid horizon
#

cause we dont have the radius

woeful stag
#

because we want to solve for the angle

rapid horizon
#

oh so divide by 25

woeful stag
#

right, or in other words: angle = s/r

woeful stag
#

I just gave you the proper steps, I have no clue what the solution is

rapid horizon
#

alright thanks tho

#

so this is what the formula for this would be right

woeful stag
#

right

#

so how do we solve for x

#

x = ..?

rapid horizon
#

divide 25

chrome patio
#

(2x+1)≡6 mod 5

#

hello how can i get this

rapid horizon
#

@woeful stag

#

this is what i got for x

woeful stag
#

thats probably it

rapid horizon
#

so is that the solution

#

because that is a answer on the multiple choice]

woeful stag
woeful stag
rapid horizon
#

damn

#

aight here is the last two

woeful stag
rapid horizon
#

ok

#

let me plug the last question

vale wigeon
#

lmao the hint is just misinformation

rapid horizon
#

uh oh hahaha

vale wigeon
#

they forgot the half

rapid horizon
#

do yk what it is tho i wanna go to sleep lmao

terse iron
#

i did this and got 8x pi if anyone can double check please

vale wigeon
rapid horizon
#

im thinking it would be number two

vale wigeon
#

incorrect

#

the height is not 14 sin(68°)

rapid horizon
whole maple
#

How do I find the turning point?

vale wigeon
#

try not to just guess randomly.

#

you know your basic trig, right?

rapid horizon
#

ig

sudden tulip
#

Any1 can assist me ?

terse iron
#

confused

#

how did u do it

pearl marlin
#

I assumed d is diameter

pearl marlin
past thicket
terse iron
pearl marlin
sudden tulip
#

yes i get it now

#

btw must i reject 1 number'

sudden tulip
pearl marlin
pearl marlin
scarlet spire
#

what are x and y

brisk inlet
#

Notation for adding an element to a set?

#

I have a set A and want to add x to it, how would I write that?

umbral pulsar
#

U

pearl marlin
umbral pulsar
#

Union

remote heron
ocean sealBOT
#

jan Niku

pearl marlin
#

Like Au{x}

brisk inlet
#

Is that really all you need? Was expecting something to signify that it was a permanent change

ionic jewel
#

A = A U {x}

pearl marlin
ionic jewel
#

ah yes A; x too

remote heron
#

just name the new set yea

#

if you need to use it more

distant socket
#

how do you do the dijkstras shortest path for this graph

ionic jewel
#

there's no tricks on this graph, it's the same way you would do it for any other one

distant socket
#

oh i just realised

#

i did the wrong one

ionic jewel
#

take the shortest path u traversed at all times, then update the shortest distance table as needed

distant socket
#

this one i mean

#

so for the first iteration D would be 2 and B would be 7 right

#

and A is 0

#

and everything else is infinity

ionic jewel
#

well you have to define iteration better than that

#

but no

#

you would take AD first, then DB

#

B would never be 7

distant socket
#

you cant go for AB?

#

how come for this example you're allowed to take 2 paths

ionic jewel
#

dijsktras always picks the shortest available path, it's a greedy algorithm

ionic jewel
#

although I'm not sure why they did it like that either

#

tou don't go two at s time unless it's modified version

distant socket
#

alright so ill just go 1 path at a time

distant socket
#

can u clarify this one @ionic jewel why is the shortest path from A to D: A,C,E,B,D I get A,C,E and D but why b

ionic jewel
#

ACEBD isnt even a valid path

distant socket
#

man

#

yea ik

ionic jewel
#

dude

#

it doesnt ask for the shorest path

distant socket
#

it says

#

attempting to solve for the shotest path??

ionic jewel
#

read what its actually asking for

distant socket
#

which order are the nodes visited

ionic jewel
#

yes

#

which should be ACEBD

distant socket
#

but theres not a valid path

#

so you dont care about the path

ionic jewel
#

it doesnt ask for the path

#

it asks for the order of nodes visited when you run dijkstras on the graph

#

and dijkstras always uses the shortest path available

distant socket
#

okok

#

so can i remember it like when i run dijkstras

#

i got ACE

#

B has to be fourth as D should be the last

ionic jewel
#

it doesnt have to visit them all

#

it does in this case though

honest umbra
#

How can I find of x and y in the geometric sequence -2, x, y, 1024

#

Wait is this channel busy oopp

ionic jewel
#

like I really dont know what else to say here that can help you, it wants you to run dijkstras and keep track of the order you visited nodes

ionic jewel
ionic jewel
#

lets make the common ratio k

honest umbra
#

I did another one that wasn’t consecutive variables

#

but this one has two variables together so idk

ionic jewel
#

ok

#

so we have

#

-2, -2k, -2k^2, -2k^3

#

you agree thats how the sequence goes with common ratio of k?

honest umbra
#

yes

ionic jewel
#

great

#

so we know -2k^3 = 1024

honest umbra
#

Yes

ionic jewel
#

,w -2k^3 = 1024

ionic jewel
#

now we found k, so you know how to find x and y from that?

honest umbra
#

-2k and -2k^2

ionic jewel
#

yep

honest umbra
#

wow u smart thx

wheat prawn
#

is this channel free now?

honest umbra
#

Yes