#geometry-and-trigonometry

1 messages Ā· Page 276 of 1

pallid cloud
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It's in 4)

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It is to be shown later

acoustic jungle
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oh sorry.

pallid cloud
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I have R=a/2sinA

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But they want me to express it in terms of let's say a b and sinC

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And S=abc/4R comes after I show that S=1/2.bcsinA and R=a/2sinA, it's not shown yet and I don't think it gonna help

acoustic jungle
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I don't think it does

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that's why i deleted the message

pallid cloud
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I think there's something wrong in the question idk why

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S can be expressed the way they asked

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And R the simplest form of it is a/2sinA

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I tried to use vector product

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I got ab=R^2.|1-|sinA|-|sinB|+|sinC|| or something like that

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I even said R=a/2sinA=b/2sinB

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So R^2=ab/4sinAsinB

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Used some trigonometric formulas

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But didn't get anywhere
Maybe I missed something or the question is wrong

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I never encountered a simple expressing of R in the form they're asking for

white dew
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Is there someone I can dm about proving trig identities.

I do not want to cut in on the problem being worked on here atm

glacial haven
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rewrite tanx and secx in terms of sinx and cosx

white dew
#

So focus on the left side, not right

glacial haven
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you can do either but left side looks easier

deep trail
silent plank
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do the same stuff to both sides of the equation to work towards isolating x

deep trail
#

divide by 23?

glacial haven
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use trig

silent plank
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that may help depending on what you do afterwards

glacial haven
#

oh wait you did

deep trail
#

cos(63)/23 = 1/x

silent plank
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(if you meant dividing both sides by 23)

deep trail
#

now im stuck

glacial haven
#

dont divide by 23

rich wolf
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Now take the reciprocal

silent plank
#

you could take the reciprocal of both sides

deep trail
#

i forgot wat that means

rich wolf
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You can do this because the reciprocal function is injective

deep trail
#

wait so just cos(63)*23 = x

silent plank
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no

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probs better to approach it another way

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from cos(63°) = 23/x
consider first multiplying both sides by x

deep trail
#

well honestly i can probably just guess from the asnwer choices i have

silent plank
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don't guess

deep trail
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oh i got it

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ty

white dew
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This is correct I hope

upper karma
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It is.

gritty sail
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can someone draw this for me

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i drew it incorrectly

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and got wrong answer

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i cant imagine it

rich wolf
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@gritty sail use geogebra

gritty sail
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how do i make it 3d @rich wolf

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nvm i found it

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uh nothing shows up

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idk how to use

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it doesnt work

rich wolf
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@gritty sail search up "geogebra 3d"

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On google

gritty sail
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i did

upper karma
dark sparrow
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!

upper karma
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@upper karma use the section of a circle formula or derive it from the circle one

pallid warren
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Hi, how do i calculate x and y axis of a triangle if i know that the hypotenuse is 10 meters and the x and y is in a different coordinate system. How do i convert x and y to be in the same coordinate system as the hypotenuse.

dark sparrow
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you mean in a different measurement system?

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i.e. that the legs are 0.3 and 0.2 respectively of an unknown length unit?

pallid warren
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ye

dark sparrow
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well

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letting x be the length of this unknown length unit in meters

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you have $(0.3x)^2 + (0.2x)^2 = 10^2$

somber coyoteBOT
pallid warren
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ye

dark sparrow
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well

pallid warren
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how do i get x, long time ago i did this kind of stuff šŸ˜„

dark sparrow
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do some algebra to it

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0.09x^2 + 0.04x^2 = 100

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0.13x^2 = 100

supple wedge
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Find, in radians, the acute angle for which $\frac{1}{(1+cosec\theta)(sec\theta-tan\theta)}=3cot\theta$

somber coyoteBOT
supple wedge
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fucking shit i overcomplicated it for myself now im stuck šŸ™‚

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ping me if u wanna help

upper karma
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Jeez

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Try putting them in terms of cos and sine

supple wedge
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u mean

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make it into non fraction?

dark sparrow
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"put things in terms of cos and sin" means "put things in terms of cos and sin"

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and then perhaps do some algebra to get rid of the skyscraper fractions

supple wedge
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lets see

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i got rid of the fraction

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cuz

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1/sec

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all that

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thats what i meant

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@dark sparrow

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idk what im doing

dark sparrow
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hhf wow you

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overcomplicated it way too much

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gonna replace $\theta$ with $x$ for simplicity:

$\frac{1}{(1 + \frac{1}{\sin(x)})(\frac{1}{\cos(x)} - \frac{\sin(x)}{\cos(x)})} = \frac{3\cos(x)}{\sin(x)} \ \frac{\sin(x)\cos(x)}{(\sin(x) + 1)(1 - \sin(x))} = \frac{3\cos(x)}{\sin(x)} \ \frac{\sin(x)\cos(x)}{1 - \sin^2(x)} = \frac{3\cos(x)}{\sin(x)} \ \frac{\sin(x)\cos(x)}{\cos^2(x)} = \frac{3\cos(x)}{\sin(x)} \ \tan(x) = 3\cot(x) \ \tan^2(x) = 3 \ \tan(x) = \sqrt{3} \ x = \pi/3$

supple wedge
#

xddddd

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o

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i am big sumb

somber coyoteBOT
supple wedge
#

dumb

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oooooooooo

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ok

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thanks <3

supple wedge
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how do i find area of equilateral triangle with side x meters and 60 dergrees

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do i use $\frac{1}{2}ab sin c$

somber coyoteBOT
acoustic jungle
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Sure

supple wedge
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i did it anyway

rich wolf
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\sin

heavy crow
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how can i use the sum to product formula on $a\sin(\alpha)-b\sin(\beta)$?

somber coyoteBOT
thorn grotto
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can you give more context on your question?

deep trail
upper karma
#

The right one if im not wrong

deep trail
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ok

upper karma
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The one in the right i mean eh

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Not the right angle lol

deep trail
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of course

upper karma
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Ok good

gritty sail
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i know i asked this but i still cant get it

heavy crow
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@thorn grotto I just want to know if its possible to use a trig identity to write that sum as a product

languid ocean
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can anyone help me with "Determine the exact value of the trigonometric functions. cosin210"

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do i literally just do cosin 210?

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(in deg)

glacial haven
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no

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use the unit circle

languid ocean
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ok i didnt think so

glacial haven
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210 is also 7pi/6 radians

languid ocean
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i watch tutorial videos and it always brings that up

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but how does that help me? they always explain it in a way i have a hard time understanding in

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let me see if i can explain which part i dont understand

glacial haven
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use this

gritty sail
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can someone help with my q i still cant get it

languid ocean
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thank you @glacial haven

dusky surge
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Jbao I'd like to help, but it's hard to explain without proper drawing tools

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Does this help?

surreal bolt
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Random Tip: trig formulas based on the unit circle for complex numbers. (less memorization or a way to check your memorized formulas)

z1 = cos(A) + isin(A)
z2 = cos(B) + isin(B)
z1 * z2 = (cos(A)cos(B) - sin(A)sin(B)) + i(sin(A)cos(B) + sin(B)cos(A)) = cos(A+B) + isin(A+B)

A = B
z1 * z2 = (cos^2(A) - sin^2(A)) + i(2sin(A)cos(A)) = cos(2A) + isin(2A)

C = 2A
cos(2A) = 1 - 2sin^2(A)
cos(C) = 1 - 2sin^2(C/2)
sin(C/2) = +/- sqrt((1 - cos(C))/2)

... and others.

gritty sail
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oh wait that said floor function! I thought that was absolute value symbol! @dusky surge thanks!

acoustic jungle
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@surreal bolt yeah I saw that in 3blue1brown quaranteen video

teal frigate
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can someone help me pls

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idk what to do?

gritty sail
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i would assume isosceles triangle

teal frigate
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what

acoustic jungle
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then use pythagorean theorem, then cosine law

teal frigate
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i srsly have no clue what im doing

acoustic jungle
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assuming that's a isoceles triangle, you can split it into two right triangles, sides with 1.3 and 1.8

teal frigate
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okay

acoustic jungle
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then you can find the third side with pythagorean theorem

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wait.

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you don't need to do that

teal frigate
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hmm

acoustic jungle
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then just use tan(x)=1.3/1.8

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then find the value of 2x

teal frigate
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tan^1(1.3/1.8) = 35.838

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thats doing something

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idk what to do next

acoustic jungle
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do you understand what you are doing

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basically we are splitting the isoceles into 2 right triangles

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does that part make sense

teal frigate
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ye i got it now

tender iron
upper karma
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@tender iron do you know the equation of a circle?

tender iron
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no

upper karma
#

Look it up on google

tender iron
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I have the equation formula - I don't understand how to fill it in

acoustic jungle
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try messing with desmos.com until you get it right, and also understand why it is right.

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(x-b)^2+(y-c)^2=r^2

upper karma
#

Oh yes

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b and c are the points at the center

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Also to clarify, they want you to express that formula in x and y terms, so:

(x-"number")^2+(y-"number")^2=number²

tender iron
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alright ty

upper karma
#

Np

upper karma
#

@spark lintel here

spark lintel
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ok

upper karma
#

Oh ok

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Use the double angle formulas that i gave you

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For tan 2x and cos 2x

spark lintel
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tan(2x)=2tan(x)/(1-tan²(x))

upper karma
#

Yeah

spark lintel
#

what about sec2x?

upper karma
#

$tan(2x)=\frac{2tan(x)}{1-tan²(x)}$

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Now

somber coyoteBOT
upper karma
#

@spark lintel as i said, put it in cos terms

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And do cos doble angle formula

spark lintel
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so we would have two fractions then?

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1/cos2x

upper karma
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Yeah

spark lintel
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and the tan

upper karma
#

Yeah

spark lintel
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are they subtracting each other?

upper karma
#

Yes

spark lintel
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One sec

upper karma
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Just tell me how it'd look after substituting the formulas

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Ok

spark lintel
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Got this ^

upper karma
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Good

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Now apply the cos double formula

spark lintel
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cos²x + sin²x

upper karma
#

cosine one is cos²x + sin²x

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Yes

tawny beacon
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Can anyone help me with a question that has been stumping people

spark lintel
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Like this ^

tawny beacon
upper karma
#

@tawny beacon occupied channel. Move

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@spark lintel yes

tawny beacon
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oof

spark lintel
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ok what are my next steps

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subtracting the fractions

upper karma
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Yeah try

spark lintel
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Not sure how

upper karma
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Look

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Tan²x=sin²x/cos²x

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Put it tan²x

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After done that, do common denominator with 1

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Lmk when you are done

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With that

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@spark lintel

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šŸ‘Œ

spark lintel
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one sec

upper karma
#

Sure

spark lintel
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Not this is it?

upper karma
#

Yes

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But do common denominator with 1

spark lintel
#

oh so this

upper karma
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Not sure what you did

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Take them away from the paper it'll look easier

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Like this

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Do common denominator on:

$1-\frac{sin²x}{cos²x}$

somber coyoteBOT
upper karma
#

Imagine this a separate exercise

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If you cant still get it, do it simpler, common denominator on:

$1-\frac{a}{b}$

somber coyoteBOT
upper karma
#

So you can visualise it better

spark lintel
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is it 1-a / 1-b ?

upper karma
#

No, eh do it with numbers

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$1 - \frac{2}{3}$

somber coyoteBOT
upper karma
#

Hint: ||common denominator is 3||

spark lintel
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1/3

upper karma
#

Yes

spark lintel
#

ah so you just subtract the numerator

rich wolf
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Yes

upper karma
#

The process is, look for common denominator(a factor that is present in both denominators), which in this case is 3 (bc 1 doesnt matter). And multiply by the common denominator with the fraction that you want to have as common denominator, which in this case we want "1" to be in common denominator. So 1/1, with the new common denominator, 3, 1/3 and multiply it with the numerator 1, so we get 3/3. So its:

$1=\frac{1}{1}=\frac{3}{3}=\frac{3}{3}-\frac{2}{3}=\frac{1}{3}$

#

@spark lintel

spark lintel
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Ah okay

somber coyoteBOT
upper karma
#

Good

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Now try again with the example with letters a and b

spark lintel
#

b-a/b ?

upper karma
#

YES

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Good good

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Now try with the cos² and sin² example

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The one we need

spark lintel
#

uhm

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cos^2x-sin^2x/cos^2x ?

upper karma
#

Yes

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:)

spark lintel
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Perfect

upper karma
#

Now notice we have

spark lintel
upper karma
#

$\frac{1}{cos²x+sin²x}-\frac{2tanx}{\frac{cos²x-sin²x}{cos²x}}$

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Yeah lol

somber coyoteBOT
upper karma
#

Now

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We'll do division in the second term

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Do:

$\frac{2tanx}{1}:\frac{cos²x-sin²x}{cos²x}$

somber coyoteBOT
upper karma
#

Now

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This is basically the second fraction we have in the original problem

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Do it

spark lintel
#

does the : represent division?

upper karma
#

Yes

spark lintel
#

ok so I think we can do

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2tanxsec^2x? as numerator

upper karma
#

Why sec?

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And not cos²?

spark lintel
#

1/sinx = secx?

upper karma
#

Dont bring back sec, we solved it before

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1/sinx = secx?
@spark lintel no, secx=1/cosx

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cscx=1/sinx

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But we dont want that here

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Just do the division

spark lintel
#

2sinx cosx / cos^2x-sin^2x ?

upper karma
#

Why 2sinx?

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Where do you get that from

spark lintel
#

hold on I screwed up one sec

upper karma
#

The denominator is ok

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Okay

spark lintel
#

Im not sure

upper karma
#

Ok just try

#

The denominator is ok

spark lintel
#

cos^2x + sin^2x / cos ^2x - sin^2x ?

upper karma
#

Id love to see from where did you got that sin^2x in the numerator

#

Its simpler than what you are may thinking

spark lintel
#

is 2sinx and sin^2x the same thing?

upper karma
#

Its cross multiplying

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is 2sinx and sin^2x the same thing?
@spark lintel no

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Its not the same a^2 than 2a

spark lintel
#

ya true

upper karma
#

Do the cross multiplying thing

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Quick i have to go sleep very soon

spark lintel
#

is the denominator: 2sinxcosx?

upper karma
#

Look, please just do cross multiplying, idk what you did there

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Also the denominator you said before was right

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Ig ill expand it

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Do:

$\frac{2tanx}{1}:\frac{cos²x-sin²x}{cos²x}$

$\frac{2tanx\cdot{cos²x}}{1\cdot({cos²x-sin²x})}$

#

@spark lintel

somber coyoteBOT
upper karma
#

I only crossed multiply

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This is the solution

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Of the common denominator obv

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And we'll remove the 1

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$\frac{2tanx\cdot{cos²x}}{cos²x-sin²x}$

somber coyoteBOT
spark lintel
#

if you cross multiplied how does 2tanx end up in the numerator ?

upper karma
#

Up down up

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Down up down

spark lintel
#

oh

upper karma
#

Kinda unclear but you get it

#

So understood everything above?

spark lintel
#

Ya cross multiplying makes it so much easier to solve now that you've explained it

upper karma
#

Good

#

Now put this back onto our original thing

spark lintel
upper karma
#

$\frac{1}{cos²x+sin²x}-\frac{2tanx\cdot{cos²x}}{cos²x-sin²x}$

#

Yes

somber coyoteBOT
upper karma
#

Ok

#

Do you know the (a-b)(a+b) identity

spark lintel
#

Not really no

upper karma
#

Put it on yt

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It'll save some time

spark lintel
#

ok

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good ^ ?

upper karma
#

Yeah lol

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Although seems a comic video

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Lol

spark lintel
#

he explains it -> (a+b)(a-b) it that fine?

upper karma
#

Yes

spark lintel
#

Oh is it just foiling?

upper karma
#

?

spark lintel
#

nvm I understand it though

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so the answer to that is

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a^2-b^2

upper karma
#

yeah

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@rich wolf can you take over me?

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I gtg sleep lol

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The original question is

rich wolf
#

Sure looks fun

upper karma
#

We are trying on RHS

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It is

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I think i can quickly resume all the steps we did

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$\frac{1}{cos²x+sin²x}-\frac{2tanx}{\frac{cos²x-sin²x}{cos²x}}$

rich wolf
#

Are you allowed to do things to both sides

somber coyoteBOT
upper karma
#

@rich wolf idk but its easier, true

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Its easier that way

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Anyway, my steps were

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After original question

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Go with double formula ^

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Tan x for sinx/cosx

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Common denominator in the second fraction below

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In the 1-sin²x/cos²x

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Which is

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$\frac{1}{cos²x+sin²x}-\frac{2tanx}{\frac{cos²x-sin²x}{cos²x}}$

somber coyoteBOT
upper karma
#

Now i made the division

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And we are here

$\frac{1}{cos²x+sin²x}-\frac{2tanx\cdot{cos²x}}{cos²x-sin²x}$

somber coyoteBOT
rich wolf
#

Equals what?

upper karma
#

Oh, but i took only the RHS

rich wolf
#

Oh i see

upper karma
#

You can do whatever you want

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Either continue this

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Or do things on both sides

rich wolf
#

How are you cross multiplying if theres no equality

upper karma
#

?

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Oh

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I call it like that lol

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Idk what to call it to explain him lol

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So yeah gl @rich wolf @spark lintel

spark lintel
#

Thanks for the help

upper karma
#

Np catthumbsup , AMD will do an amazing work as well

spark lintel
#

@rich wolf are you ready?

rich wolf
#

Sure

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Tbh i dont see exactly what al3dium is going for here

spark lintel
#

there is where we are at

rich wolf
#

Just from manipulating the right side?

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So that is equal to sec2x-tan2x ?

spark lintel
rich wolf
#

Yes but youve only done things to the right hand side

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Right?

spark lintel
#

Exactly we are trying to take the right side and make it look like the left

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you only work with one part of the equation not both

rich wolf
#

Just making sure lol

spark lintel
#

He left me off with (a-b)(a+b) identity

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@rich wolf do you know what the next step is?

rich wolf
#

Give me a sec im solving it

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On my own before i walk you through it

spark lintel
#

No problem

rich wolf
#

Ok

#

Youre gonna have to cross multiply for this problem lol

spark lintel
#

cross multiply this ?

rich wolf
#

So right now we have $\frac{cosx-sinx}{cosx+sinx}=\frac{1-sin(2x)}{cos(2x)}$

somber coyoteBOT
rich wolf
#

So

spark lintel
#

Wait what happened to the tan fraction?

rich wolf
#

Oh i just started from the beginning because tbh i dont really get what al3dium was going for

#

Pretty simple that sec2x-tan2x=(1-sin2x)/cos2x

spark lintel
#

You're not able to take a call are you?

rich wolf
#

Sorry dude i dont have a mic rn

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At my pc

spark lintel
#

ok

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so if we are proving the right side

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we shouldn't be touching the left side what so ever then

rich wolf
#

Eh it depends

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What does your teacher say

spark lintel
#

I can show you an example

rich wolf
#

No i mean what does your teacher say about proving trig identities

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What do they tell you to do

spark lintel
#

@rich wolf did you see what I sent

acoustic jungle
#

you can only prove from both sides and them make them equal

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you are not allowed to do something to both sides

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this is just a note I don't know if you did that or not

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but just a reminder

spark lintel
#

@acoustic jungle are you able to hop in a vc room

acoustic jungle
#

No because I'm like 2 years old

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I can show you what I did though

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let me try to find my phone

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@Fern#1010

#

@spark lintel

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it's a bit messy because I only had a pen

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the x is a multiplication symbol

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Fern my bread is going to mold before you come back

spark lintel
#

I got it thanks guys

merry abyss
#

@acoustic jungle mold I want to see it mold

acoustic jungle
#

@merry abyss is my father

hollow finch
#

Yo

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Can I try to help

kindred linden
#

guys i got a few questions i need help with

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anyone up for vc?

floral elbow
#

Hello how do you "find the value of the trigonometric ratio."

upper karma
#

Show us the question

floral elbow
#

We just started this in geometry

upper karma
#

So tan = opposite / adjacent

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Do u know what opposite and adjacent are

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@floral elbow

floral elbow
#

I got it. Thanks for offering to help.

upper karma
#

Ok. What did u get as the answer

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Thanks

floral elbow
#

You're welcome

upper karma
#

Mhm

floral elbow
#

I got 35/12 @upper karma

upper karma
#

Yah correct

#

Let’s gooo got it rite

ruby widget
#

i need some help

#

been at it for awhile

#

can't wrap my head around this

upper karma
#

Pls help solve it 😦

ruby widget
#

its fine guys

#

figured out somehow

upper karma
#

thx

#

Your welcome

misty plume
#

@upper karma Man of culture I see, ain't gonna leave anyone hanging

upper karma
silent plank
#

where are you stuck?

upper karma
#

calculatin da area of dis shaded region.

dark sparrow
#

if you were asked to calculate the area of the whole semicircle, would you be able to do it?

upper karma
#

yes

silent plank
#

if you were asked to calculate the area of the triangle, would you be able to do it?

upper karma
#

maybe

dark sparrow
#

there's no maybe, either you can or you can't

upper karma
#

yes

dark sparrow
#

okay

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great

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so

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does it make sense to you that your shaded region is the semicircle but with the triangle cut out

upper karma
#

yes

#

but I don't know what the radius of the semicircle is

#

and I think I need that

silent plank
#

that contradicts how you said that you could calculate the area of the semicircle

upper karma
#

yeah

#

I kinda lied

silent plank
#

consider thales's theorem.
i.e. that is a right triangle

#

which you would have needed to apply to find the area of the triangle

upper karma
#

I know the area of the triangle

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but not the semicircle

silent plank
#

and if you know 2 sides of a right triangle, what can you use to find the 3rd side?

#

(which in this case would also be the diameter)

upper karma
#

my eyes

dark sparrow
#

why thales theorem ramonov thonkzoom

silent plank
#

inscribed angle works fine i guess.

upper karma
#

pain

silent plank
#

?

upper karma
#

it never ends

silent plank
#

what never ends?

#

were you able to complete the problem or do you still need help

upper karma
#

I guess I still need help

#

I just don't pay attention to math but this is a test and I just wanna get a halfway decent grade

silent plank
#

i.e. that is a right triangle
and if you know 2 sides of a right triangle, what can you use to find the 3rd side?

upper karma
#

yeah I don't actually remember, usually for simpler problems I literally look at it and compare the length to the known sides and often it actually works out for me

silent plank
#

perhaps a famous theorem starting with Py

upper karma
#

right

#

so it's 10

#

that's what I guessed in my head

#

but now what

silent plank
#

you found that the diameter is 10
apply certain formula to find the area of the semicircle

upper karma
#

I get 50 x pi

#

but that doesn't fit any of the answers

silent plank
#

how are you getting 50*pi?

#

what formula are you applying?

#

Area of semicircle =

upper karma
#

I DID IT

#

it's A

silent plank
#

A isn't correct

upper karma
#

bruuh

#

🤯 šŸ”«

silent plank
#

what formula are you applying?
Area of semicircle =

upper karma
#

Area of semi circle is cool

#

r^2/2 x pi

silent plank
#

ok and what is r in your figure?

upper karma
#

10

silent plank
#

no

upper karma
#

Aha

silent plank
#

10 is the diameter

#

not the radius

upper karma
#

oh right

#

so we never figured out the radius

#

or I didn't

#

You didn’t

#

Son

#

@upper karma So do you know the radius?

#

no

#

What is a diameter of a circle son?

#

And what is a radius?

#

Do you see the relationship?

#

Between them

#

why are you calling me son

#

Ok Trey

#

Now answer my question Trey

#

Explain to me what a diameter and a radius is

#

random lines inside shapes that will hardly be found useful to me in the future

#

Very true but specifically random lines in circles

#

Now tell me

#

Do you know what a radius is?

#

The actual definition

#

Take your time

#

I’ll be here all day

#

šŸ™Š

#

So you do not know?

#

half of the diameter

#

šŸ™ŠšŸ™ŠšŸ™Š

#

Son, tell me... did you search that up?

#

You did not know that before

#

nope

#

I randomly remembered it

#

Oh I see

#

So just divide that diameter in 2

#

man I'm out of it

#

Ok

#

can't believe it took that long to realize

#

Alright

#

@silent plank Aight it’s your turn again

#

so the answer would be C

#

Ya idk the question just wait for Ramanov

#

do we... do we help with tests?

#

yup

#

@upper karma Ya but what’s the question

silent plank
#

yeh its C

upper karma
#

yeah

#

thank u guys for the help

#

6. Do not ask for help on tests. Any violation of this will lead to appropriate action being taken at mod discretion.

#

it's less never learning it and more forgetting everything cuz I couldn't give less of an f

#

What about open note quizzes

#

Can I ask

#

For those

#

but this was a solid refresher

dark sparrow
#

kakoolate da urrea of da shaded reejun

silent plank
#

i'd say no. don't help on things you aren't comfrotable with

dark sparrow
#

are you purposefully misspelling this

upper karma
#

Calculate

#

I just don't pay attention to math but this is a test and I just wanna get a halfway decent grade
@upper karma

#

no that's how they actually spelted it

#

The

#

Ok

dark sparrow
#

KAWKOOWAYT DAH URREUH UV DUH SCHAYDEED REEJUHN

upper karma
#

šŸ‘Œ

#

@upper karma neat

#

it's all pointless anyway

tawdry pivot
#

REEEEEEEE

upper karma
upper karma
#

@upper karma use similar triangles theorem

upper karma
#

What about 11

#

For 13 i got x = 7 btw

#

Choose to do similarity or Thales

upper karma
#

How do i prove

upper karma
#

S i m i l a r i t y

#

How many times i'll say it?

silent plank
#

consider properties of parallel lines

upper karma
#

no idea how to find

#

the angles

silent plank
#

do you know your circle theorems?

upper karma
#

uh the thing is

#

i know some

#

but not all

silent plank
#

the inscribed angle theorems

#

specifically angles subtended by the same arc

upper karma
#

a=y?

#

these are the same

#

?

#

since theyre on the same arc

#

or am i wrong

silent plank
#

alpha and gamma would be equal

upper karma
#

yeah

#

i get it now

#

thanks

#

!!

zealous ermine
#

guysss

#

what is arctan(tan^3(theta)) simplified to?

upper karma
#

@upper karma inscribed angle theorem

#

i dont know how to imply that on beta

#

The angle of a center = measure of the arc

#

So beta = measure of arc

#

And the arc you get it by inscribed angle thoerem

#

i still dont really get it :/

#

Its simple, notice that gamma and beta have the same arc

#

yes

#

because the triangle is rectangular

#

With the given angle gamma

#

Use inscribed angle with gamma and the arc

#

Understood this last step

#

?

#

oh

#

so beta is 66

#

?

#

Yup.

#

ohhhh

#

yeah that makes perfect sense

#

Glad to hear

royal cipher
#

can u use area=0.5b*h on a non-right angled triangle?

#

my book does it

#

i thought u have to do area= 0.5 * b * h * sin(a)

silent plank
#

area = 1/2 bh where h is the altitude relative to the base

royal cipher
#

even if there is no right angle in the triangle?

glacial haven
#

doesn't have to be a right angle

royal cipher
#

oh ok

#

thanks

silent plank
#

area= 0.5 * b * h * sin(a)
not a great choice of variables

royal cipher
#

yeah lol i see why

silent plank
#

= 1/2 ab sin(C)
indicates that you're using two sides and the angle between them

royal cipher
#

yup

granite elk
#

How can i solve (ii) (a)

#

(i) was ok

#

Im trying to use Tan=sin/cos in this

rich wolf
#

move all terms to the LHS

granite elk
#

Yeah i already did that

rich wolf
#

now common denominator

upper karma
#

i have the length from the middle to a point

#

and the radius of the circles taken away

#

what is the length from the middle to a point

granite elk
#

@rich wolf Im still pretty confused on what im supposed to do

acoustic jungle
#

show us what you are given

rich wolf
#

@upper karma find the circumference of each semicircle

#

There are 6 semicircles

#

=3 circles

pallid cloud
#

They don't look like semi-circles

#

They look like 6 inverted portions of a circle

#

If we turn them to the other side, they form a complete circle

#

I'm not sure about that, but I'm pretty sure each portion is not a semi-circle

silent plank
#

tangent theorems, angle around a point and angle sum of a quad will allow you to find the degree of each arc

upper karma
#

@upper karma length from middle to point is 5

granite elk
#

Im fully confused on how to solve ii a)

upper karma
#

bring everything to the left side

upper karma
#

^

#

big brain

granite elk
#

and...

silent plank
#

express tan in terms of sin and cos
multiply both sides of the equation by something to get rid of the fraction
apply a Pythagorean trig identity

upper karma
#

^

spare plaza
#

ik the simplified equation is

#

-16t^2+62x-52=0

#

but idk where to go from there

upper karma
#

Seems hot

spare plaza
#

what does that mean

upper karma
#

Seems cool

#

no u

versed river
#

You can use the quadratic formula or complete the square

upper karma
#

or use product sum factor

versed river
#

That looks very difficult to product sum

upper karma
#

oh he has -52 as his c value

#

i was using 4

#

cuz thats whats in the question

#

yah use the quadratic formula

versed river
#

Do you know how to use the quadratic formula, or how to complete the square, sam?

upper karma
#

@spare plaza

spare plaza
#

Yup i just finished it :D

fading dew
#

Hey, can someone help me real quick with a refresher geometry problem? I completely forgot how to do this lol

versed river
#

oh you're being answered in a questions channel

fading dew
#

@versed river

#

I dont know trig

#

the other guy couldn't help me

versed river
#

you could estimate it without trig, but i dont see a way to do it exactly without using trig...

fading dew
#

huh

versed river
#

is this from a geo class?

fading dew
#

yeah

#

I used to be able to do it like heckin good. but now i cant bc its been so long lmao

#

im in 10th grade

upper karma
#

Use a sum or difference formula to write a formula for cos^2x. Express the result in terms of sinx and cos2x.

#

<@&286206848099549185>

#

please

#

help

fading dew
#

what

upper karma
#

cos72

versed river
#

you sure you aren't meant to use any trig?

fading dew
#

Bro I have NEVER used trig

#

I dont understand

upper karma
#

its cos72

#

its a cofunction identity

#

trust

#

now

fading dew
#

What is the emote reaction

upper karma
#

someone fuckin help me

#

šŸ˜‚

fading dew
#

what is this

upper karma
#

Idk

fading dew
#

thanks gang

upper karma
#

I’ve seen a bot like this before

fading dew
#

twas correct

upper karma
#

It auto reacts

fading dew
#

it stopped

#

tf

upper karma
#

I created one using python

#

Cool

fading dew
#

OH MY GOD

#

i just realized something

upper karma
#

Yes?

fading dew
#

this is a p r e t e s t

#

thats why

#

Ive never used trig

#

b r u h

upper karma
#

Ah nice

#

Pre test are awesome

fading dew
#

i was so confused, I have never seen like any of this stuff b4 lmao

upper karma
#

Yep nice

#

Good luck

fading dew
#

thanks man

upper karma
#

someone help

#

please

#

Use a sum or difference formula to write a formula for cos^2x. Express the result in terms of sinx and cos2x

#

@here

#

@here

#

@here

#

@here

#

@here

#

@here

#

@here

#

@here

#

@here

#

@here

#

@here

#

@here

#

@here

#

@here

#

@here

#

@here

fluid stream
#

what have you tried

upper karma
#

i have no clue how to approach thjis

#

because

#

making cos^2x=-sin^2x+1 wont do anything

fluid stream
#

Well you are given the hint of using a sum or difference formula

upper karma
#

and expanding it to cosxcosx

#

wont do anything

#

yeah

#

thats great

#

but im gonna have to make cos^2x to become something

#

before I use those formulas

#

Im gonna need two angles to be added

#

or subtracted

#

I was thinking of doing

#

cos(x+0)cos(x-0)

#

and that does

#

absolutely nothing

fluid stream
#

you said that you can write your answer in terms of sinx and cos(2x)

#

can you expand cos(2x)?

upper karma
#

I was thinking

#

of doing a double angle formula?

#

you can expand cos2x = 2cos^x-1

#

or -2sin^2x+1

fluid stream
#

yes, that's the same thing as sum formula of cos(x+x)

upper karma
#

yea

#

where do i go from there

fluid stream
#

from cos(x+x) = cos(x)cos(x) - sin(x)sin(x) = cos^2(x) - sin^2(x)

upper karma
#

yeah

#

i realize

#

but I simplified it by substituing one of the pythagoroas identities

#

so I got

#

2cos^2x-1

#

can u just tell me the answer

#

i got 5 more min

#

before the hw closes

#

and i cant turn it in

fluid stream
#

well if you rearrange that, you get cos^2(x) = sin^2(x) + cos(2x)

upper karma
#

yeah

fluid stream
#

which should work, if not, you can use pythagorean on sin^2(x) (by adding cos^2(x) to both sides)

#

then you'll get the normal power-reducing formula for cos^2(x)

#

that is 2cos^2(x) = sin^2(x) + cos^2(x) + cos(2x) = 1 + cos(2x), so that cos^2(x) = (1+ cos(2x)) / 2

upper karma
#

ty

viscid ginkgo
#

strruggling to prove an identity

#

(sec t + 1)/tan t = tan t / (sec t - 1)

dark sparrow
#

you might consider multiplying the left-hand side by cos(t)/cos(t)

#

and perhaps also doing the same to the right-hand side

viscid ginkgo
#

but

#

I thought you had to only focus on one side

#

and find the proof from there?

#

so confusing./

#

maybe you mean, move on

#

from the left side

#

and try right

#

omfg

#

I got 0

dark sparrow
#

I thought you had to only focus on one side
there is nothing wrong with doing some simplification to the left-hand side, then independently of that doing some simplification to the right-hand side, and then proving that the simplified versions are equal

upper karma
#

ann

dark sparrow
#

what

upper karma
#

hi

dark sparrow
#

was there something else you wanted to say to me

#

beyond a greeting

upper karma
#

no

#

just wanted to say hi

glacial haven
#

hi

upper karma
#

hi

#

how has your day been

glacial haven
#

tiring

dark sparrow
#

y'all take the chatter to #chill

viscid ginkgo
#

If tanA = 5/12 with A in Q3 find sec2A

#

I don't get it

#

sec2A = 1/2sinAcosA

#

actually

#

1/1-2sin^2(5/13)

dark sparrow
#

you're missing some parentheses here

granite elk
#

How do i simplify this?

#

its supposed to give me

upper karma
#

How can an expression transform into an equation

pallid cloud
#

Akward you have an "=0" missing in the 1st pic you sent

upper karma
#

@granite elk

granite elk
#

Yeah the =0 is missing

#

but that dosent really help with the question

upper karma
#

No, but it helps us to understand the question.

#

@granite elk so are you here?

granite elk
#

Yeah

#

Original question was

upper karma
#

So, do common denominator

granite elk
upper karma
#

From what you got, do common denominator

granite elk
#

i simplified what i got

upper karma
#

From this ^, do common denominator

granite elk
#

Thats what i got

upper karma
#

What? Can you follow my instructions

granite elk
#

?

upper karma
#

Do common denominator on the full expression

#

You should get up to $\frac{1-\cos²{x}}{\cos{x}}-(\frac{3\cos²{x}-2\cos{2}}{\cos{x}})$

#

@granite elk

royal cipher
#

the fact he pinged akward

#

nice

#

hahaha

upper karma
#

Lmao

granite elk
#

rip

upper karma
#

Mmm

#

You should get up to $\frac{1-\cos²{x}}{\cos{x}}-(\frac{3\cos²{x}-2\cos{x}}{\cos{x}})$

granite elk
#

ohh

#

thanks

royal cipher
upper karma
#

Lol

royal cipher
#

akward u havea great name and pfp

granite elk
#

lol thx

somber coyoteBOT
upper karma
#

Now

#

Follow this? @granite elk i only did common denominator which was what i told you to do for 5 mins

granite elk
#

ok

upper karma
#

Understood this step?

granite elk
#

yeah

upper karma
#

Ok isnt a proper answer lol

#

Good

#

Now

granite elk
#

is that minus meant to be there

#

next to the brackets

#

because its going to affect the - inthe 2 cos

upper karma
#

Substracting

$1-\cos²{x}-3\cos²{x}+2\cos{x}$

somber coyoteBOT
upper karma
#

is that minus meant to be there
@granite elk yes it is

granite elk
#

ok

upper karma
#

And thats about it

#

Substracting

$1-4\cos²{x}+2\cos{x}$

somber coyoteBOT
upper karma
#

Arranging it

#

$4\cos²{x}+2\cos{x}+1=0$

#

Which is what you wanted to get

somber coyoteBOT
granite elk
#

Thanks

#

it finally makes sense now

upper karma
#

Np catthumbsup

strong pilot
upper karma
#

@strong pilot state the formula for an hexagonal pyramid

#

Here on this chat

strong pilot
#

SA = hp + b?

upper karma
#

SA?

strong pilot
#

surface area

upper karma
#

No its $A_{total}=(\frac{b*h}{2})*6 + A_{base}}$

strong pilot
#

what does the a represent

upper karma
#

A, area

#

p perimeter

#

Ap, apothem

#

Wait

#

My bad

somber coyoteBOT
upper karma
#

Now lol

strong pilot
#

ok that makes more sense kinda

upper karma
#

Ok now

strong pilot
#

what would atotal represent

upper karma
#

Uhh wait lemme read it again

#

@strong pilot the area of the whole thing

strong pilot
#

oh ok

#

alrighty lemme try this

#

tysm

upper karma
#

Okok np

upper karma
#

Gonna ask this here again, how to find the perimeter? Didn't quite get the answer I was looking for last time.

I have the length from the middle to the point (5cm) and the length of the radius of the circles that are taken away from the sides (also 5cm)

I need to find the perimeter, but I don't know how.

#

visually, its scuffed

#

cause if the circles werent taken away then the original circle would be the same size as the circles taken away

brisk ginkgo
#

Can someone dm I’m so confuseeed

#

<@&286206848099549185>

acoustic jungle
#

@upper karma assuming that shape is a hexagon, the perimter is just the circumference of the circle

#

if you construct another circle connecting the the radius of the star, it'll be a rhombus

#

with 60 degrees

#

and there are 6 of them

brisk ginkgo
#

I NEED HELP PLSSSSs

upper karma
#

@brisk ginkgo just post it bruh

upper karma
#

@brisk ginkgo "help, help, I need help", 5 minutes later he's offline

#

Lmao

#

what I understand from that is that the test is over and he's no longer interested in getting help

#

Prob ^

#

Which is pretty sad and dissapointing

brisk ginkgo
#

No it’s a review!

#

Not a test

upper karma
#

Post it!

#

post the problem that you need help with

brisk ginkgo
#

HELP HELP HRLP PLS

upper karma
#

haven't you learned to figure this out in class or something

brisk ginkgo
#

I’m saying no and our teacher doesn’t teach in class

#

I mean zoom class

#

We don’t have like classes for math

upper karma
#

you dont have zoom classes for math?

#

damn