#geometry-and-trigonometry

1 messages Β· Page 256 of 1

rich wolf
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y=tan(1)

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you want the tangent of 1 radian?

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or 1 degree?

golden panther
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i guess 1 degree

cinder portal
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tan(1) degree?

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holy

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wat

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i mean your answer is going to be

golden panther
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Bro I dont know

cinder portal
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super SUPER nasty

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it's possible

golden panther
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it doesnt say

weary drift
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$\tan(1)$ or $\tan\inv(1)$?

cinder portal
#

best way without calculator is just messing with identities

somber coyoteBOT
cinder portal
#

oh fair point

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inverse or regular

golden panther
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the right one

cinder portal
#

oh

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nvm

rich wolf
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one of those is super easy

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the other one is super hard

cinder portal
#

you got this then

golden panther
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what is the best way

rich wolf
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ok

weary drift
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ask yourself what angle between -pi/2 and pi/2 is such that tan of that angle produces 1

rich wolf
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you are trying to find tan(x)=1

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what is the definition of tan?

golden panther
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sin/cos

rich wolf
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so if sin/cos=1, what does that imply

golden panther
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@weary drift i dont have the unit circle memorized yet

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that its already 1?

rich wolf
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no

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if i have two numbers

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a and b

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and i tell you that a/b=1

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can you solve for a

golden panther
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yes

rich wolf
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what is a

golden panther
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b*1

rich wolf
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so a = b

golden panther
#

yes

rich wolf
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so in this scenario

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a is sin(x), and b is cos(x)

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at what angle is sin(x)=cos(x)

golden panther
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do i need the unit circle memorized for this

rich wolf
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kind of

golden panther
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crap

cinder portal
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guess and check

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lol

rich wolf
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not really tho if you know your special right triangles

cinder portal
#

hint: it involves pi

golden panther
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Nah im just going to open a new tab

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i have the degrees memorized just not the square roots

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Its 45

cinder portal
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πŸ‘

golden panther
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bro dont roast

cinder portal
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not roasting

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good job

golden panther
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oh ok

cinder portal
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i guess the clap does look a bit sarcastic

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didnt mean it that way

golden panther
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so i have to memorize the square root part of the unit circle to do these

compact spire
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Can anyone help me with this? been trying it out myself but I can't even finish it without getting a super crazy number

cinder portal
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try this

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$\sin^{-1}(- \frac{3}{5}) = \alpha \
\tan^{-1}(\frac{2}{7}) = \beta$

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holy shit

somber coyoteBOT
cinder portal
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make this substitution

compact spire
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I've done that for the difference of sine

cinder portal
#

what did you get

plucky jacinth
cinder portal
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use tr

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ig

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set up your equation

compact spire
plucky jacinth
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i have no clue how to do this

cinder portal
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WAT

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when you do what I told you to do, you should just get this

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$\sin{\alpha - \beta}$

somber coyoteBOT
cinder portal
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ok just use the substitution

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it's a lot easier

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you don't have to write much

compact spire
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okay so sin (a-b) = sin(a)cos(b)-sin(b)cos(a)

cinder portal
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use the sin subtraction identity

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yes

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and then evaluate each term individually

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in order to do this

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you have to know the domain of your inverse trigonometry

compact spire
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yeah I am lost with finding the domain of the inverse.

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So is this where I find out which quadrant they are in?

cinder portal
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yea do that

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figure out which trig function has domain in which quadrants

compact spire
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so a = Q2 and b = Q1

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Okay, so I've been trying to figure out the rest of this and im having trouble with the 2/7 part. when completing the triangle I keep getting sqaure root of 53.

rich wolf
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And whats the problem with sqrt53

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Is it not pretty enough

compact spire
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Im just not sure if im doing it wrong

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so it would be (-3/5)(7sqrt53/53)-(2sqrt53/53)(-4/5)

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I think I know where I messed up.

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Thanks for the help @cinder portal and @rich wolf

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the (-4/5) is supposed to be (4/5)

plucky jacinth
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can anyone help me in a way that it will help

dark sparrow
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@cinder portal parentheses

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$\sin(\alpha - \beta)$

somber coyoteBOT
cinder portal
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😦

dark sparrow
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@plucky jacinth what is giving you trouble here?

plucky jacinth
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all of it

dark sparrow
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vague!

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okay, so how familiar are you with the basics of trigonometry

plucky jacinth
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0

dark sparrow
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does the mnemonic "SOH CAH TOA" ring any bells

cinder portal
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lol i thought u hated mnemonic

dark sparrow
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it's a definitional mnemonic. the one exception.

plucky jacinth
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no i have not been to school for 2 weeks

dark sparrow
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have this, then.

compact spire
#

@cinder portal so with a calculator I got -0.79 etc and without using one I got 94.64 for that problem you were helping me with

cinder portal
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try to get an exact answer

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calculator is cheating

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lol

compact spire
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so 94.64 is better to use

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I hate using calculators but I use them to reference what I should aim for in an answer, should I not be doing that?

cinder portal
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actually try to compute each term

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you can do it without a calculator

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and the answer comes out incredibly nice

compact spire
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I want to find that answer so bad now

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okay

rich wolf
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Use WA step by step

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Or symbolab

dark sparrow
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symbolab thonkBan

compact spire
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@rich wolf what are those?

dark sparrow
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don't bother with symbolab. it's crap.

rich wolf
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Say what you want about symbolab but its free

dark sparrow
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it's free crap.

rich wolf
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Photomath also works

dark sparrow
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that's even more crap

rich wolf
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WA is of course top tier

compact spire
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what is WA

rich wolf
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But sometimes you dont feel like matching your grouping symbols

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Also kind of expensive

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@compact spire it is an easy way to get answers

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But dont use it unless you're really stuck on something

compact spire
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Im really stuck on all my homework im doing because school is cancelled and my professor is leaving us to learn everything on our own. But thank you all for the help so far. I greatly appreciate it.

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OMG

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I think I got it

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(-3/5)(7sqrt53/53)-(2sqrt53/53)(4/5) = -29sqrt53/265

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@cinder portal

cinder portal
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looks correct

compact spire
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YES!

cinder portal
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compare it with ur calculator

compact spire
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my calculator says im an idiot

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checking now

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I GOT IT

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OMG I did the math!

cinder portal
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nice

compact spire
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Thank you so much

cinder portal
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no need, u did all the work

compact spire
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Is there a limit of help I can ask for?

rich wolf
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@compact spire no more than once every minute

compact spire
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Okay

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so im pretty sure I just sub the tan-1x for a and sin-1y for B and do the difference of cosine

cinder portal
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yup

compact spire
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which has me at cos a cos B - sin a sin B

cinder portal
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the rest are easy

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ur formula is wrong though

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it should be a +

compact spire
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oh really?

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I thought since it was minus it would be minus, is it the opposite of what is shown?

white cradle
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ye

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cos(A+B) = cosAcosB - sinAsinB

compact spire
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Okay thanks guys

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so I need to complete the triangle I assume

dark sparrow
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well you WILL need to simplify $\cos(\arctan(x))$, $\sin(\arctan(x))$, $\cos(\arcsin(y))$ and $\sin(\arcsin(y))$

somber coyoteBOT
compact spire
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simplify?

dark sparrow
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uh

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yes

cinder portal
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do the same thing

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you got this

compact spire
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Okay

cinder portal
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$x = \frac{x}{1}$

somber coyoteBOT
cinder portal
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that's the hint for ya

compact spire
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so sqrt 1+x^2 = the hyp

dark sparrow
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sqrt**(1+x^2)**

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now if only you'd marked the angle arctan(x) on the triangle

compact spire
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how do you mean?

dark sparrow
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i mean exactly what i said

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if you had marked the angle arctan(x) in your triangle, you'd be able to find its sine and cosine with ease now

compact spire
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Im sorry, my brain isnt processing so well. been working like crazy

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Okay, I think I got it

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$frac{sqrt{1-y^2} + xy}{sqrt{1 +x^2}}$

somber coyoteBOT
dark sparrow
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\ \ \ \ \ \

compact spire
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Was trying to learn but didnt workout

dark sparrow
#

you droped some of these

compact spire
#

$\frac{sqrt{1-y^2} + xy}{sqrt{1 +x^2}}$

somber coyoteBOT
compact spire
#

omg lol

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$\frac{\sqrt{1-y^2} + xy}{\sqrt{1 +x^2}}$

somber coyoteBOT
compact spire
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Okay, thats what I got.

dark sparrow
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for the final answer?

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looks sus

compact spire
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I will look over it again then

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Okay so im back to this point

dark sparrow
#

ok so this actually was alright and it really did only look sus and that's it

compact spire
#

so it was right

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Im so nervous i feel sick. lol

upper karma
dense trail
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Is e the ans

upper karma
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Is e the ans
@dense trail 😦

dense trail
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Option e

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I am just asking bec of the black mark

upper karma
#

Is e the ans
@dense trail the ans is c

dense trail
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Are there any relation betwwn the radii of the circle

upper karma
#

Are there any relation betwwn the radii of the circle
@dense trail idk

dense trail
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Its not working

compact spire
#

Okay im back, does anyone know what I should google to learn how to solve this problem? I have 0 clue on how to solve this

rich wolf
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@compact spire use a graphing calculator

compact spire
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I don't have one.

rich wolf
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Uh desmos should work

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Or maybe WA

compact spire
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like this?

rich wolf
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Sure

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Remember the domain

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2pi is 6.28

compact spire
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so .14 and 3.0

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Thanks for the help @rich wolf

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the formula is 2sinxcosx

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=2(3/5)(4/5)

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=2(12/5)

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am I on the right track?

umbral snow
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That's exactly right

compact spire
#

=24/5 ?

umbral snow
#

Oh oop. (3/5)(4/5) = 12/25

compact spire
#

okay

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=2(12/25)

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=24/25

umbral snow
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You can also use a calculator to confirm the answer. It is correct here.

compact spire
#

Awesome, thank you

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okay so half angle formula would be cosx/2 = +- sqrt 1+cos2x/2

umbral snow
#

I tried

compact spire
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I will try it again

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hopefully it works lol

umbral snow
#

cos(x/2) = ±√[(1 + cos(x))/2]

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So you want to plug in x = 45 here

somber coyoteBOT
#

Pony Boy:

$ cos(\frac{x}{2}) = Β± \frac{\sqrt{1+cos(x)}{2}$
```Compile error! Output:

! File ended while scanning use of \frac .
<inserted text>
\par
<*> 98531807913349120.tex

I suspect you have forgotten a }', causing me to read past where you wanted me to stop. I'll try to recover; but if the error is serious, you'd better type E' or `X' now and fix your file.

compact spire
#

nevermind

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lol

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but you get it

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where did you get 45? @umbral snow

umbral snow
#

If x is 45, then the left side is cos(22.5) which is what we want

compact spire
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Okay thats what I was thinking

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I thought I had to plug in 22.5 in for x

umbral snow
#

You could try it, but you'll find quickly it doesn't work here

compact spire
#

Okay

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so ±√[(1+cos(45))/2]

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do I just plug this into a calculator?

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wait

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cos of 45 is just √2/2

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so = √[(1+√2/2)/2]

umbral snow
#

Yep, that's a way you can express it

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You can clean it up a little by multiplying numerator and denominator by 2

compact spire
#

$=\frac{\sqrt{2+\sqrt{2}}}{2}$

somber coyoteBOT
umbral snow
#

Yus that works

compact spire
#

Okay

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Okay, this I was never taught as well

dark sparrow
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double angle identities no bueno?

compact spire
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Well I was supposed to learn double and half angle this week but schools been cancelled so im trying to learn on my own

umbral snow
#

Nothing you aren't capable of. That Β² should scream "quadratic" at you, so see if you can get rid of the cos(2x)

dark sparrow
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cos(2x) = 2cos^2(x) - 1

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this is the only identity you need here really

upper karma
compact spire
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So I should get the cos2x alone?

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cos2x = 2-2cos^2x

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?

dark sparrow
#

bruh.

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cos(2x) = 2cos^2(x) - 1

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this identity. apply it.

compact spire
#

so far im at 4cos^2(x)-3=0

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am I on the right track so far?

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cos(x)= √(3/2)

umbral snow
#

Gotem

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Wait you mean
cos(x) = √3 / 2

compact spire
#

yeah

umbral snow
#

If you're lit with your unit circle, that should ring a bell

compact spire
#

pi/6

umbral snow
#

Also [0, 2Ο€) solution range

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You're correct with Ο€/6

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The other would have been 11Ο€/6

compact spire
#

11pi/6

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okay

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I need a break, thanks for the help.

viscid ginkgo
dark sparrow
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@compact spire what about cos(x) = -sqrt(3)/2

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you forgot that pensive_grapes

plucky jacinth
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this hurts me

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i have 2 hours to take and turn in a test i have no idea on how do this

dark sparrow
#

this is arccos(13/20)

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simply by SOH CAH TOA

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there is nothing else to this

plucky jacinth
#

40.5416018735

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@dark sparrow 49.4583981265

dark sparrow
#

were you asked to round to ten decimal places

plucky jacinth
#

yes

dark sparrow
#

to ten decimal places?

stone quiver
plucky jacinth
stone quiver
#

I am getting 64/40 can someone check?

dark sparrow
#

@plucky jacinth ANGLES should be rounded to the NEAREST DEGREE, and even otherwise there's a BIG DIFFERENCE between "TEN DECIMAL PLACES" and "TO THE NEAREST TENTH"

plucky jacinth
#

so 49.5

dark sparrow
#

ANGLES.

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should be rounded.

plucky jacinth
#

49

dark sparrow
#

to the NEAREST DEGREE.

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there we go

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rounding Ο€ to the nearest tenth gives 3.1
while rounding Ο€ to ten decimal places gives 3.1415926536

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just so you know

plucky jacinth
#

27/38

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arctan

stone quiver
plucky jacinth
#

35

paper mauve
#

$$\tan(\theta)=\frac{opposite}{adjacent}

somber coyoteBOT
paper mauve
#

so since we want theta we take the inverse of tangent

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of both sides

plucky jacinth
#

soo arctan(27/38)

paper mauve
#

yes

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bingo

plucky jacinth
#

35.394795845

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ya

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so 35

paper mauve
#

so the thing here i want you to do is to draw what is given

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@plucky jacinth

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if you can, take a picture of your drawing with the given dimensions in the right places

plucky jacinth
#

sin68 x/15

paper mauve
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$$sin(68)=\frac{x}{15}

somber coyoteBOT
paper mauve
#

yes

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very good

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@plucky jacinth

compact spire
plucky jacinth
#

how would i put that into a a calculator

dark sparrow
#

@paper mauve \sin

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@plucky jacinth you wouldn't, unless you're allergic to algebra you should be able to solve this rather simple equation for x

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$x = 15 \sin(68)$

somber coyoteBOT
compact spire
#

so I googled double angle identities and I have 3 options I guess for cos2(x) so I can use 2cos^2(x)-1

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is that correct?

paper mauve
#

@dark sparrow ty

compact spire
#

$2cos^2(x) - 1$

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my answer from my problem was -7/25 can anyone confirm that for me?

somber coyoteBOT
compact spire
#

$2(\frac{3}{5})^2 - 1$

somber coyoteBOT
compact spire
#

$2(\frac{9}{25})-1$

somber coyoteBOT
compact spire
#

$\frac{18}{25}-\frac{25}{25}$

somber coyoteBOT
compact spire
#

$= -\frac{7}{25}$

somber coyoteBOT
compact spire
#

Can someone help me with reducing cos^4(x) to the first power?

stone quiver
#

Can you reduce cosΒ²x into first power ?

compact spire
#

ehhh

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not really

stone quiver
#

wait, you want linear terms with the same angle i.e x and not like 2x or sth?

compact spire
#

My professor never taught us anything like this so I'm trying to learn on my own since he can't

stone quiver
#

Isn't $((1+cos2 x)/2)^2)$ a valid answer then?

somber coyoteBOT
compact spire
#

How would I get rid of the fraction in that situation

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because it says to factor out all fractions

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so $cos^2(x) = \frac{1}{2}[1+cos2(x)]$

somber coyoteBOT
compact spire
#

that's correct?

stone quiver
#

yes

compact spire
#

okay so if it were the fourth power it would just be

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$cos^4(x) = (\frac{1}{2}[1+cos2(x)])^2$

somber coyoteBOT
stone quiver
#

Yea exactly

compact spire
#

Okay, so far so good.

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I have the $\frac{1}{2}$

somber coyoteBOT
compact spire
#

which I need to get rid of as it says in the problem

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how would I go about doing that

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or am I just overthinking it

gentle dome
#

I have a strange question.

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When I was looking at how Archimedes approximated Pi, I was wondering about a few assumptions.

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When he was inscribing and circumscribing a circle with polygons, how can he assume that the circumference is between the two perimeters?

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I can also draw a picture like this.

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In my 2nd diagram, you can easily see that the white perimeter is way bigger than the outer square.

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If he were comparing the area of the circle with the area of the two polygons, it would be obvious to understand, but I’m troubled that he used perimeters instead.

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Can anyone help me in any information or step I’m missing?

upper karma
#

Can sum 1 help me with number 4 on this

languid hemlock
#

I dont know how to find AE

silent plank
#

bisecting and intersecting chords theorem

rain galleon
#

We are given 2 radius's and the distance between centers, no other information, how do I find the area of the intersection?

supple wedge
#

can u send the full qn

upper karma
#

Hi, can someone help me out with this triangle? I'm given the angle in A and told that the bisectors of B and C intersect at I (incenter). I have to find the angle BIC.

#

,rotate

somber coyoteBOT
upper karma
#

nvm

crisp phoenix
#

hey, so i have a quiz on circles coming up, would anyone be able to help me find the answers while im doing it? would highly appreciate it since theres some very smart ppl in here

idle bloom
#

no

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we will help you understand the concepts before the quiz

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but while you're doing the quiz you're on your own

viscid ginkgo
#

how lis line BC perpendicular to line l?

silent plank
#

it's not?

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who's saying it is

viscid ginkgo
#

I drew it wrong my bad

#

someone else answered , thanks though.

golden panther
#

YO! guys how do i find sin^2(15Β°) and cos^2(22.5Β°)

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Plz guys?

coral sapphire
#

Is there any comments on how you should do it?

golden panther
#

No

coral sapphire
#

Then, just plug it into the calculator if you don't need an exact form

golden panther
#

Wth

silent plank
#

they probably do want exact form

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consider half angle identities

golden panther
#

Ok i see

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Thx Fam

ionic bluff
#

hello friends

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i have a kind of dumb question

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how exactly is multiplication and division defined geometrically

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i've been thinking about the tangent function

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and how it is sin/cos

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i get that sin is vertical

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and cos is the horizontal part

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but what does the tangent of that tirangle look like

dark sparrow
#

how exactly is multiplication and division defined geometrically
wdym

livid epoch
#

$arg(\frac{z_2-z_1}{z_3-z_2})$ what is argument coudl someone help?

somber coyoteBOT
livid epoch
#

please this is very tricky

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@umbral snow please this is very tricky

umbral snow
#

but what does the tangent of that tirangle look like
@ionic bluff
The tangent is the slope of the terminal arm

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z2 - z1 is the line AB

livid epoch
#

ye

umbral snow
#

z3 - z2 is the line BC

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When you divide one complex number by another, you subtract their angles

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That is,
Arg(a/b) = Arg(a) - Arg(b)

livid epoch
#

yes yes

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i got marked incorrect i do not know why

umbral snow
#

I'm not crazy certain what the arg of either is

reef wren
#

Hi. I have some struggles with proofs in coordinate geometry. From the textbooks I saw, it seems to be common practice to only prove statements in the first quadrant. So, for example, say I wanna find general equation for a line that has intercepts with axes of x and y at a and b at the respective axes. Then its equation will be:

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$\frac{x}{a} + \frac{y}{b} = 1$

somber coyoteBOT
reef wren
#

And almost always, when authors prove it, they 1. Pick up a line that has positive a and b intercepts, 2. Pick up a point on the line that is in first quadrant.

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I want to know, why do they do so? Is there's a reason why we don't have to prove statements in other quadrants? Does proof in the first quadrant immediately applies to any other quadrant? Is there a shortcut(s) for proving for all the quadrants and their combinations(i.e., say a line might occupy 1, 2 and 4 quadrants, or 1, 2 and 3.)?

dense trail
#

Well may be becasuse of the sense

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@livid epoch

steady forum
#

Is answer cos(90-theta)=sine theta

dark sparrow
#

there's like 6 problems here all with multiple subproblems

steady forum
#

So its cos(90-35)=sine 55

dark sparrow
#

which one are you talking about

steady forum
#

3i

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3i my bad

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So sine 55= cos 35

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Right

dark sparrow
#

yes

steady forum
#

So

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Its because of formula right thats why i get 35

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Cos(90-x)=sinx

steady forum
#

Question 3ii

silent plank
#

zoom in please

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we aren't hawks

steady forum
#

Im wrong alr

#

All my workings r wrong

#

Anyone

silent plank
#

the work is unclear

#

atm i can only see sin(40Β°) = cos(50Β°)

steady forum
#

My workings r all not relevant to question

silent plank
#

can you do anything/ apply any identities to:
cos(310Β°)?

steady forum
#

Not to my knowledge

silent plank
#

express in terms of relative angle?

steady forum
#

Relative angle?

#

-cos50?

silent plank
#

not -

steady forum
#

Cos(-50)

#

?

white cradle
#

thats just cos50

silent plank
#

^

steady forum
#

Z

white cradle
#

cos is positive in fourth quadrant

steady forum
#

Rite

silent plank
#

which gets you: $\cos^2(50\deg)$

somber coyoteBOT
silent plank
#

and you should be able to get the required answer now

steady forum
#

Idgi

silent plank
#

idgi?

steady forum
#

I dun gte it

#

Get

white cradle
#

i dont get it

#

lol

silent plank
#

how ironic

white cradle
#

whats the question actually

silent plank
#

3ii

steady forum
#

3ii

silent plank
#

here you can apply something very famous

white cradle
#

i cant read it ;-;

silent plank
#

those most common trig identity

white cradle
#

nvm

#

got it

silent plank
#

which is essentially pythagoras

steady forum
#

Wtf

#

Idgi

silent plank
#

$\sin^2(x) + \cos^2(x) = 1$

somber coyoteBOT
steady forum
#

Why wld i apply that

#

I dont have any squares

white cradle
#

because you know sin(50)=b

steady forum
#

I dont even know how u got cos^250

#

Cos^2(50)

silent plank
#

you had sin(40Β°) = cos(50Β°) right?

steady forum
#

Yes

white cradle
#

oh lmao

#

right

silent plank
#

and we established just then that cos(310Β°) is also equal to cos(50Β°) right?

steady forum
#

Yes

white cradle
#

so there is your cos^2(50)

steady forum
#

Wait

#

Wait why is it equals again

white cradle
#

oof

silent plank
#

which gets you
cos(50Β°) * cos(50Β°) = cos^2(50Β°)

white cradle
#

cos(310) = cos(-50) = cos(50)

silent plank
#

cos is 360Β° periodic and even

steady forum
#

Oh ya cuz in

#

Then 4th quad

#

Everything becomes pos

#

Cos(50) =/= b or a

#

Sine 40 =/= b or a

white cradle
#

sin(40)=cos(50)

#

are you even reading ramonov's messages

steady forum
#

Sine 40 isnt b or a in the question

white cradle
#

sin(40)=cos(50)

#

sin(40)=cos(50)

#

sin(40)=cos(50)

#

sin(40)=cos(50)

steady forum
#

Yes i got that

#

In my working

#

From sine 90- theta= cos thea

white cradle
#

so the whole expression becomes cos^2(50)

silent plank
#

which gets you
cos(50Β°) * cos(50Β°) = cos^2(50Β°)

white cradle
#

^

steady forum
#

They want me to express the equation in b or a

white cradle
#

that is what we're trying to do..

silent plank
#

$\sin^2(x) + \cos^2(x) = 1$

somber coyoteBOT
silent plank
#

$\sin^2(50\deg) + \cos^2(50\deg) = 1$

somber coyoteBOT
silent plank
#

do you see a or b anywhere there?

white cradle
#

aw cmon

silent plank
#

hah

steady forum
#

Sine(50)=b

white cradle
#

custom tex 😠

steady forum
#

Sine^2(50)= b

white cradle
#

no

silent plank
#

no

steady forum
#

B^2

silent plank
#

still questionable

white cradle
#

^

silent plank
#

math is case senstive

white cradle
#

lol

steady forum
#

b^2

white cradle
#

yes

#

so..

steady forum
#

Haiz

silent plank
#

and what's your final answer

steady forum
#

Cos^2(50)=1-b^2

#

Because its essentially cos(50) Γ— cos (50)

silent plank
#

lowercase cos but seems ok

steady forum
#

Thanks

vague lance
#

This can’t be right

#

?

lament pumice
#

Not at all.

vague lance
#

do you think you could explain it

lament pumice
#

Sure, the formula you wrote for a cosine of an angle works only for angles between cathetus and hypothenuse

supple wedge
#

@vague lance why would u choose 90

#

use theta

#

cosΞΈ=AB/1
=AB

golden panther
#

YO! do i need to calculator to find the max of y=2cos^2(x/2) in the closed interval from -Ο€/2 to 3Ο€/2?

burnt bolt
#

No. Think about the shape of the cos(x/2) graph and where it would be a maximum then work out what the maximum y value for your specific function would be in that interval

rapid pollen
#

I don’t understand the law of sine

somber coyoteBOT
coral sapphire
#

What do you not get?

rapid pollen
#

I’ll show you

#

I just don’t understand how to use the formula

#

Or law

coral sapphire
#

A better way to phrase it in English is that the law of sines states "the ratio of any side and the sine of the opposite angle are the same"

#

Since you already have the triangles labelled, you can just plug values into the equation

#

Lets look at the last triangle you posted

rapid pollen
#

Ok

coral sapphire
#

Wait, you did it correctly

rapid pollen
#

Wait for angles is it b/B sin

#

And for degrees is it B/bsin

#

Or is it the same for both

coral sapphire
#

Neither of those statements are valid

#

What is the argument of sin?

rapid pollen
#

Opposite over hypotenuse

coral sapphire
#

Wait for angles is it b/B sin
@rapid pollen

rapid pollen
#

Yes

coral sapphire
#

I meant what is this referring to? Sin has no argument

rapid pollen
#

I mean for the equation a/sin A= b/Bsin

coral sapphire
#

b/sinB?

rapid pollen
#

I’ll send

coral sapphire
#

Ok, the work is perfect

#

What's wrong thonkzoom

rapid pollen
#

Oh it is

coral sapphire
#

Yeah, this is correct

rapid pollen
#

I’m just tired I should go to sleep lol. I’m studying for pre calculus after trigonometry what’s next?

coral sapphire
#

Law of cosines if you didn't learn it yet

#

Then, you will probably learn about graphing trig functions

rapid pollen
#

Is that the same as law of sines

coral sapphire
#

No

#

Law of cosines and law of sines are different

rapid pollen
#

Ok

#

Does graphing and functions use algebra 2

coral sapphire
#

Uhhh, yeah

rapid pollen
#

Sounds great πŸ‘

crisp phoenix
#

hi

#

can someone pls help me w this

coral sapphire
#

Is there more info?

crisp phoenix
#

no i dont think so

#

i just need to find the measure of angle ABO

coral sapphire
#

Not enough info

#

Also, it says correct answer below is 22 degrees

crisp phoenix
#

yeah thats what i think it is

coral sapphire
#

Wdym think

crisp phoenix
#

also poco this one

coral sapphire
#

That is the answer

crisp phoenix
#

theres

#

the full question so

#

those answers are random not correct

coral sapphire
#

Try it yourself first

crisp phoenix
#

i did

#

thats why i need help

coral sapphire
#

So the stuff entered is what you think is correct

crisp phoenix
#

no

#

pretend they arent there

coral sapphire
#

Last 3 are wrong

#

The angles are not exactly the arc the encompass

crisp phoenix
#

ok poco

#

how would i find angle WVU

coral sapphire
#

What is arc WTU

crisp phoenix
#

230 degrees

coral sapphire
#

So do you know any theorems relating an inscribed angle to the arc it intercepts

crisp phoenix
#

ok wvu would be 115 correct?

#

yeah the intercepted arc is half the length of the arc length right?

coral sapphire
#

Yes

#

Now do the same for the rest

crisp phoenix
#

21 for the last 2 right

#

?

coral sapphire
#

Should be

crisp phoenix
#

ok poco

#

i have another one

#

how would i go about finding this

#

nvm i got

#

it

coral sapphire
#

Please stop pinging me for every question, expecting me to be there

quiet mason
#

what have you tried btw

#

what formulas do you know

coral sapphire
#

He already got it

viscid ginkgo
#

And the line is not tranversal right, it would have to be a straight angle

#

So the sum should be 80 + 30?

silent plank
#

,rotate

somber coyoteBOT
viscid ginkgo
#

sorry about that, cool bot though

silent plank
#

And the line is not tranversal right, it would have to be a straight angle
what's that in reference to

viscid ginkgo
#

the line that is in the middle of the parallel lines

#

that breaks into two pieces

silent plank
#

that'd be 2 separate lines

viscid ginkgo
#

ok

#

so it's just a case of alternate interior angles

silent plank
#

yes

viscid ginkgo
#

y is 80, x is 30

#

ty

#

there's a theorem here that says alternate interior angles formed by two lines cut by a tranversal are congruent if and only if the lines are parallel

#

so I wonder how does the problem I Showed you relate to this

plain pollen
lament pumice
#

Are you asking why half of the length of cross product equals half of the area between two vectors?

plain pollen
#

Uh, well. My teacher just showed us that the area formula for a triangle can be rewritten as half of the vector product of a and b

#

And I'm trying to find a mathematical proof for that

lament pumice
#

Basically, cross product is defined to have a length of a parallelogram between those two vectors and if you connect any two opposite points of a parallelogram you'd divide it in half(because two those triangles are equal because their sides are equal).

white cradle
#

area* not length

lament pumice
#

Or that formula could be proven without cross product. Just take a regular formula with triangle height and express that height using sine.

white cradle
#

magnitude of cross product = area of parallelogram

plain pollen
#

oh and 1/2*parallelogram is a triangle

lament pumice
#

Sure, I never said length of a parallelogram, I've said length of a cross product.

white cradle
#

Basically, cross product is defined to have a length of a parallelogram between those two vectors

plain pollen
#

lol

lament pumice
#

Lol, how did I write that, hah

white cradle
#

missed a word ig

#

lol

lament pumice
#

Nah, what I meant is that a vector of a cross product has length equal to the area of that parallelogram.

plain pollen
#

oh and the cross product of two vectors yields a perpendicular vector?

#

is that a given?

lament pumice
#

Yep, that's part of a definition

plain pollen
#

wait but how is that relevant here? Is it? lol I'm confusing myself

lament pumice
#

Nah, in that case we don't care at all where our vectors point.

uncut cradle
#

can someone give me SOHCAHTOA problems?

dark sparrow
#

gimme a moment.

uncut cradle
#

tnks bro

dark sparrow
#

i'm not your "bro". and would prefer not to be addressed as such.

#

make sure to read the instructions carefully.
if you want to check your answers then pm them to me indicating which problem you're giving me the answer to. but do take note that i can and will reject answers which are not properly formatted. you may omit the degree sign in problems that ask you to find the angle.

uncut cradle
#

ok ok thank youu

storm cave
#

Can anyone help me with my math soon

dark sparrow
#

wdym soon

#

why can't you post the thing you need help with now

storm cave
#

I took a look at it before, had a lot of trouble with it, took out the dog and I’ll be back soon

steady forum
#

whats the diff

#

between

#

things like

#

-tan (theta) and tan(-theta)?

dark sparrow
#

wdym by "things like"

steady forum
#

the two i stated

dark sparrow
#

i mean, tan(-ΞΈ) = -tan(ΞΈ) for all ΞΈ where both sides make sense

#

but if you didn't know anything about tan, then you could not say automatically that negating the input and then passing it through the function would just so happen to produce the same result as passing your input through the function and then negating the output

steady forum
#

So its similar but diff

dark sparrow
#

...

#

tan(-ΞΈ) and -tan(ΞΈ) are EQUAL.

#

functions for which this thing works are called "odd functions"

steady forum
dark sparrow
#

"the" steps?

steady forum
#

Working

dark sparrow
#

if they asked for -tan(ΞΈ) then maybe you could cut the step where tan(-ΞΈ) is replaced by -tan(ΞΈ) out of the solution

#

so maybe no the exact set of steps could differ

steady forum
#

What the heck

dark sparrow
#

you ask a stupid question you get a stupid answer

steady forum
#

:(

dark sparrow
#

"what's the difference between these two things that are actually the same"

#

"would The Stepsℒ️ differ for these two superficially different problems even though each problem admits multiple different sequences of steps to solve it so the question as stated just doesn't make any sense and there is no constructive answer to it"

steady forum
#

Okay

#

Thanks

storm cave
#

How am I supposed to get A?

dark sparrow
#

consider that you can calculate the lengths of DB and EB

storm cave
#

I'll try

#

How would I go about calculating EB?

supple wedge
#

EB is the opposite side of triangle BDE

#

and 8 is the hyp

#

so u should use $sin25=\frac{8}{EB}$ and solve for EB

somber coyoteBOT
supple wedge
#

@storm cave

storm cave
#

Ohhh I see! Thank you!

supple wedge
#

:))

dark sparrow
#

uh

#

this is wrong @supple wedge @storm cave

supple wedge
#

he said EB

#

πŸ˜›

dark sparrow
#

yes EB

storm cave
#

For EB?

supple wedge
#

isnt it sin

#

opp/hyp

dark sparrow
#

it's $\sin(25) = \frac{EB}{8}$

somber coyoteBOT
supple wedge
#

fuck(

dark sparrow
#

8 is the hypotenuse.

supple wedge
#

REEEEEEEEEEEEEEEEEEEE

#

hahhahhahhahahhahaha i am rart

#

sure

#

thanks st. big brain ann

storm cave
#

The answer is -0,016... I doubt thats correct.... Is it my calculator?

supple wedge
#

wrong because i am fucking stupid

#

$sin25=\frac {EB}{8}$

somber coyoteBOT
supple wedge
#

hehe

storm cave
#

Oh wait

#

The answer for that is -1.05... I think I'm missing something

supple wedge
#

,w calculate sin 25

somber coyoteBOT
supple wedge
#

,w calculate 8(sin25)

somber coyoteBOT
supple wedge
#

there u go @storm cave

storm cave
#

It's my calculator.... Sin(25) gives me -0.13

#

Any idea how to fix that?

#

TI-84 Plus

#

Also thank you

supple wedge
#

did u put in radian

#

or degree

storm cave
#

Radian

supple wedge
#

its supposed to be in degree

storm cave
#

Ohh yes I see, thank you!

supple wedge
#

because 25

#

for DB just use some pythagoras theorem

#

same for AB

#

then subtract

storm cave
#

Wait do I need DB to get A?

supple wedge
#

yes

#

wait i thought u were finding a length mb

#

ignore the subtract part

#

after u find AB use cosA to find A

storm cave
#

isnt it tan?

supple wedge
#

yes

#

omg

#

my ratios

#

are shit

#

for fucks sake

#

tan

#

yes

storm cave
#

You're good, thanks for the help man :)

supple wedge
#

sorry for fucking up my ratios so badly omg

storm cave
#

It's fine man, ty!

#

If C1 has r = 2 and C2 has r = 3, how do you go about calculating PS?

grizzled zinc
golden panther
#

lel

grizzled zinc
#

Yo nvm had to inverse

quiet mason
#

@storm cave what have you tried

storm cave
#

nothing much.... I dont understand it at all

quiet mason
#

do you know what similar triangles are or trigonometry

rich wolf
#

,w calculate sin(25 rad)

somber coyoteBOT
spice ridge
#

can someone help me with this question?

#

its 4 right?

rich wolf
#

@spice ridge no

#

You are wrong

spice ridge
#

then what is it?

#

i graphed both on desmos and its a mirror

#

thats not very helpful by just saying im wrong

rich wolf
#

@spice ridge

#

Does this look like something mirrored across the line y=x

spice ridge
#

must've put in a different equation my bad

rich wolf
#

Lmao

upper karma
#

f(x) =1,5x-18
g(x)=0.5x+6

how can i calulate the angle?

wind heart
#

Does anyone know how to do this? I got it wrong and I have no idea how to to get -5,7

lyric lichen
#

I think I can help, imagine a coordinate grid, and the point (3, -1) on it, if we reflect it across the line y = 3 (a horizontal line that crosses (0, 3)) then we just take the distance the current point is from the line and move it that length away in the other direction

#

That's not a great explanation, but in this case, since the y value of (3, -1) is 4 away from +3, the new y value is 4 away on the opposite side of the line

#

(3 + 4 = 7, so the new point is at (x, 7)) then do the same thing across the vertical line x = -1

#

@wind heart feel free to ping me if you need any further assistance :)

wind heart
#

Oh thanks sm!

upper karma
#

@loud pike ?

loud pike
#

oh wait nvm

#

I misunderstood what it was saying

upper karma
#

btw here's a geo problem it's kinda competition math

#

Solution:
||So what I did was first make the square into a 3x3 grid. The total area is 9. Then, I drew the diagonal from the top left to the bottom right. That diagonal will divide the square into 1/2, so you know that the non-hashed area divided by that diagonal is 9/2. Then you want to find the area of that trapezoid, so you set up two equations:
y = -x + 2
y = -3x + 3
Solve for the system of equations:
-x + 2 = -3x + 3
2x = 1
x = 1/2
y = 3/2
Now, find the distance from that to (2,0), which is root(2)/2.
The other side is similar, so you subtract the 2(root(2)/2) from 2(root(2)).
You then get root(2). That is the first base of the trapezoid.
You can get the second base, which is just the diagonal, which is 3(root(3)).
If you have the grid drawn out, you can recognize that the height of the trapezoid is root(2)/2.
The average of root(2) and 3(root(2)) is 2(root(2)).
Now, multiply root(2)/2 and 2(root(2) to find the area of the trapezoid.
You get 2.
9/2 + 2 = 13/2
(13/2)/9 = 13/18
But don't forget that we have only calculated for the non-hashed out area!
The final solution is 5/18!||

lyric lichen
#

That's awesome, I'll give it a go, wish me luck

lilac isle
dark sparrow
#

is the tank meant to be cylindrical

lilac isle
#

I believe so

dark sparrow
#

aight so

#

it's made of half-inch-thick steel

lilac isle
#

yup

dark sparrow
#

and it stands to reason that 15 ft and 20 ft are the dimensions of the interior of the tank

#

ie the part that actually holds water

lilac isle
#

15-ft in diameter and 20-ft tall.

dark sparrow
#

so really it's a cylinder with a diameter of 15'1" and a height of 20'1" with a hole inside shaped like a cylinder of diameter 15' and 20'

#

1 inch bc the half-inch of steel contributes to the diameter and height on both sides

#

anyway, with that in mind, you should be able to figure out the volume of steel used in the making of the tank

lilac isle
#

yup

dark sparrow
#

and once you have the volume, you can get the mass

#

since you have the density

lilac isle
#

I think I see what you talking about

#

gimme me a min to calculate it

dark sparrow
#

yeah ofc i'm leaving the specific calculations to you

#

in part bc i'm a bit too lazy to do them

lilac isle
#

πŸ‘πŸΏ

dark sparrow
#

so i don't think i can check them if you send them to me

lilac isle
#

it fine, thank!

dark sparrow
#

alright yeah i guess i'm gonna have to ask for help again lmao

#

let Ξ±, Ξ² and Ξ³ be the angles of a triangle. prove that sin(Ξ±)sin(Ξ²)sin(Ξ³) ≀ 3sqrt(3)/8 and find all triangles for which this inequality becomes an equality

#

i have a hunch that equality holds iff Ξ±=Ξ²=Ξ³=Ο€/3 and i've tried naΓ―vely applying am-gm but this didn't really get me anywhere productive

#

where a, b and c are the sides of the triangle and S is the area

#

but honestly i have little to no clue how to progress

#

i've got another four of these angle inequality problems and honestly i'm just as stuck on them as on this one

#

hang on

#

i think i have an idea.

#

yeah nvm, i solved it.

#

turns out jensen's inequality did the trick lmfao

viscid ginkgo
#

how can I prove that x is 35?

#

the remote interior angles on the left should be 60 + 70 = 130, but that won't work.

#

x = 35.

dark sparrow
#

what's known about that angle next to x

viscid ginkgo
#

nothing

#

x = 35 is the answer actually

dark sparrow
#

nothing? then x need not be 35

#

are you sure you aren't omitting some crucial info

viscid ginkgo
#

yeah man

#

the middle line is not even straight, so it doesn't seem like a bisector.

dark sparrow
#

the middle line can be swung back and forth as much as you want within that triangle, and x will change but none of the other data will

#

so you MUST be omitting some info

#

can you show the problem exactly as stated

viscid ginkgo
#

I'm really not omitting any info

#

but I'll redraw it.

cinder portal
#

do what Ann tells you

#

show the problem exactly as stated

viscid ginkgo
#

it's even less info lol

#

actually I missed the y

#

but same thing

cinder portal
#

ok yea this question is broken

viscid ginkgo
#

lol

flint osprey
#

who gave you a question in the format of ms paint?

viscid ginkgo
#

I copied it from my book.

#

ms paint is just useful as hell for this lol

#

would be nice for a more professional software

flint osprey
#

so you drew this, it's not the original problem

#

you really should take the advice that's given to you and take a picture of the problem

viscid ginkgo
#

lol I drew it exactly but ok I'll take a picture

cinder portal
#

its fine, we cant track where you are when you send a pic

viscid ginkgo
#

lmao

#

they make a lot of spelling errors in this book, probably rushed

viscid ginkgo
#

ok now I'm stuck on #17

#

I don't see same side interior angles, corresponding angles, alternate interior or exterior angles

#

I tried using the remote interior angles trick

#

that doesn't help either

silent plank
#

were you able to find x?

#

||xΒ° and 30Β° are alternate interior||

viscid ginkgo
#

my best guess so far is that y is 30 degrees

#

possible alternate interior angle

silent plank
#

^ did you get x?

viscid ginkgo
#

no

#

I saw the answer in the book but no

#

I don't think y is 30 though, it could easily be 20

#

by same logic

silent plank
#

well x is alternate interior to the 30Β°
are you able to spot it after i tell you?

viscid ginkgo
#

ah yeah I see that

silent plank
#

and then to find y, consider the external angle theorem

#

and/or angle sum of triangle + angle sum on straight line

viscid ginkgo
#

thanks

ruby inlet
#

Need some help: is sin(wt-phi) = -sin(wt+phi)?

gritty siren
#

it doesn't quite work with phi=0 for example

daring solstice
#

Bc the radius isnt give.

#

*given

#

Bros plz help

dim sable
#

i need help i have a test on this tomorrow

#

can some one help me study'

timber coral
upper karma
lament pumice
#

Oh yes, the geometry question

upper karma
#

@timber coral how would i go about finding the locus

#

it's just a quartercircle

#

right

timber coral
#

yesthank you

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26quonbarkley i believe it is circle equation

pure pivot
solid sequoia
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I'm trying to find the equation of the hyperbola: Foci (0,-8), (0,8); difference of focal radii is 10

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I've been looking online for hours on how to solve this problem and all I can muster up is that apparently C = 8, which means that A = 4. But 64 = 16 + B^2 makes B = positive negative 6.92820323028 please halp

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wind heart
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That’s my answer, and this is the correct answer

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I’m confused. What does it mean to reflect the line over the line of reflection? Like,

silent plank
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read the instructions

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it seems its indicated by x=6

wind heart
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How would I know to change it over the x axis? I don’t get it

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Ohhhhh

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I see

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So like

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Your supposed to count the things

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And the points are equal opposites