#geometry-and-trigonometry | Mathematics | Page 152

lost hare Sep 19, 2017, 2:49 AM

#

lol

fallow sapphire Sep 19, 2017, 2:49 AM

#

Okay so

#

After I get two points I can get the rest without doing it?

#

or do I still have to do them

crude kraken Sep 19, 2017, 2:49 AM

#

You can get the rest if it's a line

fallow sapphire Sep 19, 2017, 2:50 AM

#

Okay

crude kraken Sep 19, 2017, 2:50 AM

#

So, try graphing y=3x-2

fallow sapphire Sep 19, 2017, 2:51 AM

#

is that (0,2)?

crude kraken Sep 19, 2017, 2:51 AM

#

No

fallow sapphire Sep 19, 2017, 2:51 AM

#

or (3,2)?

crude kraken Sep 19, 2017, 2:51 AM

#

3x**-**2

fallow sapphire Sep 19, 2017, 2:51 AM

#

oh -

#

so its 0,-2?

crude kraken Sep 19, 2017, 2:51 AM

#

Mhm

#

And, what's the next point? Rise over run

fallow sapphire Sep 19, 2017, 2:51 AM

#

so it would be going down the graph

#

uhh

#

(1,-3)?

#

or (1,0)

crude kraken Sep 19, 2017, 2:52 AM

#

Neither

fallow sapphire Sep 19, 2017, 2:52 AM

#

oh

crude kraken Sep 19, 2017, 2:52 AM

#

3/1 = up 3, right 1

#

You know your first point is 0,-2, so what happens when you move up 3, right 1?

fallow sapphire Sep 19, 2017, 2:53 AM

#

(3,-1)

crude kraken Sep 19, 2017, 2:53 AM

#

(1,1)

fallow sapphire Sep 19, 2017, 2:53 AM

#

Ohhhh

#

Rise 1 Run 2

#

from the other one

crude kraken Sep 19, 2017, 2:54 AM

#

(-2 + 3 = 1, 0 + 1 = 1)

fallow sapphire Sep 19, 2017, 2:54 AM

#

ohhhhh

#

ohh

#

Okay

crude kraken Sep 19, 2017, 2:54 AM

#

Mhm

#

https://www.desmos.com/calculator/2rnqgoa6a4 Here's something where you can mess with m and b to see what happens as you change them

Desmos Graphing Calculator

Lines: Slope Intercept Form

fallow sapphire Sep 19, 2017, 2:55 AM

#

so from the 3x, the 3 = the rise?

crude kraken Sep 19, 2017, 2:55 AM

#

Mhm

fallow sapphire Sep 19, 2017, 2:55 AM

#

oh

crude kraken Sep 19, 2017, 2:55 AM

#

Rise over run, 3 = 3/1

fallow sapphire Sep 19, 2017, 2:55 AM

#

so if I have an equation like this

#

y=5x-3

#

it would be run 5?

crude kraken Sep 19, 2017, 2:56 AM

#

No, rise 5

#

run 1

fallow sapphire Sep 19, 2017, 2:56 AM

#

ooh

crude kraken Sep 19, 2017, 2:56 AM

#

Rise is how much you move up, run is how much you move right

fallow sapphire Sep 19, 2017, 2:56 AM

#

Yea I meat rise

#

and the run is 1 because x isn't there?

crude kraken Sep 19, 2017, 2:57 AM

#

The run is 1 because, 5/1

fallow sapphire Sep 19, 2017, 2:57 AM

#

Because x is 1?

crude kraken Sep 19, 2017, 2:57 AM

#

Not necessarily

#

Like with 1/2

#

x = +2 when y = +1

fallow sapphire Sep 19, 2017, 2:57 AM

#

mm

#

okay

crude kraken Sep 19, 2017, 2:58 AM

#

Get it?

fallow sapphire Sep 19, 2017, 2:58 AM

#

Sorta

#

like

#

if its a fraction it represents both the rise and run?

#

1/2 = rise 1 run 2?

crude kraken Sep 19, 2017, 2:59 AM

#

Mhm

fallow sapphire Sep 19, 2017, 2:59 AM

#

@lost hare are you seeing this too?

#

ooh

lost hare Sep 19, 2017, 2:59 AM

#

m

#

i am trying to get help myself

fallow sapphire Sep 19, 2017, 2:59 AM

#

So if it is not a fraction, the x represents the run

#

ok go do that

#

and if there is, the denominator represents the run

#

right?

crude kraken Sep 19, 2017, 2:59 AM

#

if it's not a fraction, rewrite it as one

#

Is 5 not equal to 5/1?

fallow sapphire Sep 19, 2017, 3:00 AM

#

Yeah

#

So, if its y=5x-3

#

the x has nothing on it so its like a (1)x

#

so its 5/1

#

so rise 5 run 1

#

right?

crude kraken Sep 19, 2017, 3:00 AM

#

Mhm

fallow sapphire Sep 19, 2017, 3:00 AM

#

oooh

crude kraken Sep 19, 2017, 3:00 AM

#

Starting at (0,-3) because -3 is the y intercept

#

So your two points are (0,-3) and (1,2), you draw a line from those you and you're done

fallow sapphire Sep 19, 2017, 3:01 AM

#

Sweet!

crude kraken Sep 19, 2017, 3:02 AM

#

One thing you should learn is that a graph is just relating x to y.

fallow sapphire Sep 19, 2017, 3:02 AM

#

Okay

chilly prism Sep 19, 2017, 3:02 AM

#

@crude kraken can you help me

crude kraken Sep 19, 2017, 3:03 AM

#

y=2x looks like this because y is 2x, so as x = 2, y = 4

📎 unknown.png

#

@chilly prism With?

fallow sapphire Sep 19, 2017, 3:03 AM

#

okay thank you

#

i've learnt enough tonight, thank you, peak you're in good hands

chilly prism Sep 19, 2017, 3:03 AM

#

the sum of the measures of two angles is 180 . one angle measures 3a and the other angle measures 2a - 25 find a then find the measurements of each angle

crude kraken Sep 19, 2017, 3:04 AM

#

=tex 3a + (2a-25) = 180

charred spearBOT Sep 19, 2017, 3:04 AM

#

📎 latex.png

crude kraken Sep 19, 2017, 3:04 AM

#

Just solve that algebraically for a

chilly prism Sep 19, 2017, 3:05 AM

#

do i do distributive porperty

crude kraken Sep 19, 2017, 3:05 AM

#

=tex 2a-25 = 180-3a \text{ or } 2a-25 = -3a+180

charred spearBOT Sep 19, 2017, 3:05 AM

#

📎 latex.png

chilly prism Sep 19, 2017, 3:05 AM

#

2 of the angles have to be the same

#

since its a triangle

crude kraken Sep 19, 2017, 3:06 AM

#

You simply said that the two angles add up to 180

chilly prism Sep 19, 2017, 3:06 AM

#

lol nevermidn

crude kraken Sep 19, 2017, 3:06 AM

#

:?

#

2a = 205 - 3a

#

5a = 205

#

205/5 = 41

#

a = 41

chilly prism Sep 19, 2017, 3:08 AM

#

i got that

#

thax

crude kraken Sep 19, 2017, 3:09 AM

#

;p

chilly prism Sep 19, 2017, 3:09 AM

#

4x + 2 = 3x

#

subract 4x from both sides right

#

@crude kraken

crude kraken Sep 19, 2017, 3:09 AM

#

Easier to subtract 3x

#

But yea

chilly prism Sep 19, 2017, 3:09 AM

#

1x = 2

#

?

crude kraken Sep 19, 2017, 3:10 AM

#

if you subtract 4x, you get 2 = -1x, if you subtract 3x, you get x + 2 = 0

chilly prism Sep 19, 2017, 3:10 AM

#

4x = 2 + 3x

#

can i reverse it like that

crude kraken Sep 19, 2017, 3:10 AM

#

No

#

=tex 4x+2-2 = 3x-2

charred spearBOT Sep 19, 2017, 3:11 AM

#

📎 latex.png

chilly prism Sep 19, 2017, 3:11 AM

#

so x + -2

#

i mean

#

x = -2

crude kraken Sep 19, 2017, 3:12 AM

#

Mhm

umbral rivet Sep 19, 2017, 3:21 AM

#

Toast

#

💖

#

🍞

crude kraken Sep 19, 2017, 3:35 AM

#

🍞

umbral rivet Sep 19, 2017, 11:11 AM

#

👀

dark sparrow Sep 19, 2017, 11:26 AM

#

👀

blissful hill Sep 19, 2017, 11:45 AM

#

Too hard

daring cedar Sep 19, 2017, 6:08 PM

#

Guys

#

My teacher wants me to know what certain equations are without using a graphing calculator. How tf do I know if an equation is linear, absolute, maximum or min, or etc

sacred bison Sep 19, 2017, 6:14 PM

#

from their formulas

umbral rivet Sep 19, 2017, 6:14 PM

#

^

sacred bison Sep 19, 2017, 6:14 PM

#

y=mx+b is linear for instance

#

📎 1460905908514.jpg

dark sparrow Sep 19, 2017, 6:15 PM

#

templates

#

not formulae

#

y = mx + b is a template

umbral rivet Sep 19, 2017, 6:16 PM

#

Omg

dark sparrow Sep 19, 2017, 6:16 PM

#

this is what all linear equations look like

umbral rivet Sep 19, 2017, 6:16 PM

#

That image is amazing

sacred bison Sep 19, 2017, 6:16 PM

#

@dark sparrow sorry, english is not my first language

dark sparrow Sep 19, 2017, 6:16 PM

#

i mean dw

#

"template" is not a term i've heard from others

#

but i think it's a good term

#

y = |ax + b| + c
this is the template for absolute value functions

umbral rivet Sep 19, 2017, 6:17 PM

#

🤔

daring cedar Sep 19, 2017, 6:24 PM

#

Now heres the real biggie

#

how tf do u draw a curve on a graph

dark sparrow Sep 19, 2017, 6:24 PM

#

depends on what kind of curve

daring cedar Sep 19, 2017, 6:25 PM

#

arent quadratics kinda curvy

#

something like that

dark sparrow Sep 19, 2017, 6:25 PM

#

parabolas

maiden trench Sep 19, 2017, 6:29 PM

#

They're like Us or upside down Us.

#

Depending on the sign of the x^2 term

daring cedar Sep 19, 2017, 6:36 PM

#

📎 More_junky.PNG

#

this is my homework for instance

#

I have no idea how to find a min or max

maiden trench Sep 19, 2017, 6:44 PM

#

Hmm, it helps to have idea of the general shapes. For example, 6 part c. Would any line at all have a maximum or minimum?

#

And when it comes to quadratics, eventually the squared term is most important. Like x^2 - 59999999 (as an example) will be negative for ages, but it will eventually be positive and tend to infinity. If it were -x^2 + something else, it would be the opposite. It would eventually tend to negative infinity.

quick mural Sep 19, 2017, 7:03 PM

#

I like "template." It's more elegant that "general form of the equation."

upper karma Sep 19, 2017, 7:35 PM

#

📎 IMG_20170919_212306.jpg

#

Hello,
What is the triangle OEF?
We know that AO is a radius of the circle.
that EF = 5 cm
that EO = 12cm
that OA = 13 cm

#

I use google translate (i'm french)

#

Help me

dense crater Sep 19, 2017, 8:14 PM

#

Test¨

upper karma Sep 19, 2017, 8:20 PM

#

?

whole onyx Sep 19, 2017, 8:34 PM

#

What do you mean by "what is the triangle OEF"? I doubt you want someone to tell you what type it is. What is the objective of the problem?

#

I understand you're French, so I understand

upper karma Sep 19, 2017, 8:52 PM

#

sorry @whole onyx What nature is it?

umbral rivet Sep 19, 2017, 9:41 PM

#

uwu

whole onyx Sep 19, 2017, 10:34 PM

#

If I'm not mistaking your question, a scalene right triangle...

OF is also the radius, and it fits for the pythagorean theorem (only works for right triangles: 5^2+12^2=13^2). I feel that I'm not answering the right question still...

inner patrol Sep 20, 2017, 2:48 AM

#

pls help

#

I need to find the total area of this

📎 image.png

#

I found the circumference of this ''circle'' which is 62,8339 cm

📎 image.png

#

and idk what to do now

cunning zinc Sep 20, 2017, 2:51 AM

#

if you have the cirumference, you can find the radius, and then the sector that is depicted

#

since you have the inside angle

inner patrol Sep 20, 2017, 2:51 AM

#

how do I find the radius

cunning zinc Sep 20, 2017, 2:51 AM

#

C = 2 pi r

inner patrol Sep 20, 2017, 2:51 AM

#

thanks

#

I have a math test tomorrow

cunning zinc Sep 20, 2017, 2:52 AM

#

no problem

#

I have homework due and no one can seem to help me with my questions lol

#

or wants to, is probably more accurate

inner patrol Sep 20, 2017, 2:52 AM

#

I'm only in 9th grade lol

cunning zinc Sep 20, 2017, 2:53 AM

#

I didn't mean you specifically lol

inner patrol Sep 20, 2017, 2:53 AM

#

when I get the radius what will I do

cunning zinc Sep 20, 2017, 2:55 AM

#

do you know what a sector is?

topaz valley Sep 20, 2017, 2:55 AM

#

@cunning zinc people only want to help with stuff they're good at. my ability to answer multivariate calc questions has no reflection on, say, my knowlege of sets, or geometry

inner patrol Sep 20, 2017, 2:55 AM

#

yup a part of a circle

cunning zinc Sep 20, 2017, 2:55 AM

#

I didn't say they weren't capable people @topaz valley lol

#

do you know how to calculate the area of a sector?

inner patrol Sep 20, 2017, 2:56 AM

#

yup

cunning zinc Sep 20, 2017, 2:56 AM

#

what is the equation?

inner patrol Sep 20, 2017, 2:58 AM

#

📎 image.png

#

but idk whats the total area of the circle

cunning zinc Sep 20, 2017, 2:59 AM

#

you don't know the area of a circle?

#

the equation for it?

inner patrol Sep 20, 2017, 2:59 AM

#

I know it

#

but idk the area of said circle

#

in the math problem

cunning zinc Sep 20, 2017, 3:00 AM

#

you don't need to know the area specifically

#

just the equaiton, you can do some simplificaton

inner patrol Sep 20, 2017, 3:00 AM

#

how

cunning zinc Sep 20, 2017, 3:01 AM

#

well actually, just what's the area of any circle?

inner patrol Sep 20, 2017, 3:01 AM

#

I found the radius

#

its 10,0003 centimeters

cunning zinc Sep 20, 2017, 3:01 AM

#

you can do it all in terms of variables for now, and just plug in values after you formulate the answer

#

formulate meaning...figure out what the answer looks like, then plug in for the variables

#

so area of any circle is A = ?

inner patrol Sep 20, 2017, 3:02 AM

#

sorry if I don't understand

#

im bad at math

#

yeah

#

oh no wait

#

I know now

#

I need to do pi x 10,0003 squared

#

that will give me the total area of the circle

cunning zinc Sep 20, 2017, 3:04 AM

#

yes

#

then multiply by the degree fraction for the sector

inner patrol Sep 20, 2017, 3:04 AM

#

yeah!

cunning zinc Sep 20, 2017, 3:04 AM

#

or the angle fraction

inner patrol Sep 20, 2017, 3:04 AM

#

thanks!

cunning zinc Sep 20, 2017, 3:04 AM

#

not a problem, sorry if the help was a bit slow, I like to push people to think themselves instead of just spitting out the answers

#

helps you more that way ;)

inner patrol Sep 20, 2017, 3:05 AM

#

thanks

#

I like your way of teaching!

cunning zinc Sep 20, 2017, 3:08 AM

#

thanks

inner patrol Sep 20, 2017, 3:08 AM

#

I gtg sleep

#

wish me luck for my exam!

cunning zinc Sep 20, 2017, 3:08 AM

#

lol

#

good luck

inner patrol Sep 20, 2017, 3:08 AM

#

goodnight! 😃

#

thanks!

inner patrol Sep 20, 2017, 3:23 AM

#

oh wait

#

I forgot to ask

#

how can I find the other side of the square

📎 image.png

cunning zinc Sep 20, 2017, 3:25 AM

#

is it a square or a rectangle?

inner patrol Sep 20, 2017, 3:25 AM

#

its 3 squares

cunning zinc Sep 20, 2017, 3:25 AM

#

or just a rectangle*

#

squares have the same length on every side

inner patrol Sep 20, 2017, 3:25 AM

#

ummm not in that case

cunning zinc Sep 20, 2017, 3:26 AM

#

if they are rectangles only, then that's not necessarily true, but if they are squares, all the sides are the same length

inner patrol Sep 20, 2017, 3:26 AM

#

my teacher said they're only the same lenght if there's lines of isometry

cunning zinc Sep 20, 2017, 3:26 AM

#

all sqaures are rectangles (quadrilateral with all 90 degree angles)

#

not all rectangles are squares

#

well idk then, you said squares, so I assumed they were defined as squares

inner patrol Sep 20, 2017, 3:27 AM

#

im confused

#

I mean the 3 squares would make a rectangle

#

pls help

cunning zinc Sep 20, 2017, 3:28 AM

#

each of them is a square?

#

so each side of the square has the same length

inner patrol Sep 20, 2017, 3:29 AM

#

this is exactly what is on my sheet

📎 image.png

cunning zinc Sep 20, 2017, 3:29 AM

#

oh

inner patrol Sep 20, 2017, 3:29 AM

#

it says ''Calculate the total area of the package shown here''

cunning zinc Sep 20, 2017, 3:29 AM

#

is the 14.19 the sector arc length or the side of the rectangle?

inner patrol Sep 20, 2017, 3:30 AM

#

idk

cunning zinc Sep 20, 2017, 3:31 AM

#

there's nothing else?

inner patrol Sep 20, 2017, 3:31 AM

#

nope

#

well the 14,19 is above the arc but also above the side of the square

#

which is confusing

#

if this is ever brought up in an exam imma ask my teacher

#

what the measure is

cunning zinc Sep 20, 2017, 3:33 AM

#

perhaps, the scale is not correct and it is both?

#

the arc length is the same as the side of the rectangle?

inner patrol Sep 20, 2017, 3:33 AM

#

maybr

#

maybe

cunning zinc Sep 20, 2017, 3:33 AM

#

I know the arc is curved, but it still doesn't look right based on the scale, then again the circle doesn't look like a circle :P

#

but it could be the value for both

inner patrol Sep 20, 2017, 3:53 AM

#

I need help with another problem

#

theres a painted cone
and it is rolled on a square cardboard, therefore making a circle
and they wanna know
how much full circles beside eachother can we paint on it
and the area of the carboard thats not painted

topaz valley Sep 20, 2017, 3:54 AM

#

how much full circles beside eachother can we paint on it

#

this part is confusing me

inner patrol Sep 20, 2017, 3:57 AM

#

heres the drawing they supplied

📎 image.png

topaz valley Sep 20, 2017, 3:59 AM

#

well it depends how big the cardboard is

inner patrol Sep 20, 2017, 4:03 AM

#

heres what I think it is

📎 image.png

#

The cardboard is 4096cm

#

the image is what I meant by this

📎 image.png

topaz valley Sep 20, 2017, 4:04 AM

#

so just horizontally?

#

not vertically

inner patrol Sep 20, 2017, 4:05 AM

#

It has to take the whole cardboard

topaz valley Sep 20, 2017, 4:05 AM

#

but how big is the cardboard

inner patrol Sep 20, 2017, 4:06 AM

#

64 by 64 cm

topaz valley Sep 20, 2017, 4:06 AM

#

oh, ok

#

so how big is one circle?

inner patrol Sep 20, 2017, 4:06 AM

#

''A painter sprays a sponge in the shape of a cone with paint to reproduce small or large circles.''

topaz valley Sep 20, 2017, 4:08 AM

#

given the information in your first picture, do you know how big one of the circles is?

inner patrol Sep 20, 2017, 4:09 AM

#

''By rolling the sponge on its side face, a large circle is obtained. What will be the unpainted surface of the 64 cm square cardboard on which the biggest amount possible of full circles side-by-side are painted".

#

nope

#

here is what they gave me

📎 image.png

topaz valley Sep 20, 2017, 4:09 AM

#

so if we painted that and rolled it on the ground, which part of the cone will be touching the ground?

inner patrol Sep 20, 2017, 4:10 AM

#

its hard to explain

#

basically he wants to cover the surface area of the cardboard with circles

topaz valley Sep 20, 2017, 4:10 AM

#

yes no I get that

inner patrol Sep 20, 2017, 4:10 AM

#

but the circles have to be in a line

topaz valley Sep 20, 2017, 4:10 AM

#

I'm asking you

inner patrol Sep 20, 2017, 4:10 AM

#

and they have to be full

topaz valley Sep 20, 2017, 4:10 AM

#

which part of the cone is touching the ground

inner patrol Sep 20, 2017, 4:10 AM

#

not like half a circle

#

that part

📎 image.png

topaz valley Sep 20, 2017, 4:11 AM

#

yes

#

the sides

inner patrol Sep 20, 2017, 4:11 AM

#

everything except the base

topaz valley Sep 20, 2017, 4:11 AM

#

so how long is the slanted side of the cone?

inner patrol Sep 20, 2017, 4:12 AM

#

Ohhh

#

so its c squared = a squared + b squared all over again

topaz valley Sep 20, 2017, 4:12 AM

#

yeah

inner patrol Sep 20, 2017, 4:12 AM

#

thanks

#

lemme try

#

okay so the hypotenuse is 4,1231 cm

#

wait

#

I think I got it

#

the hypotenuse would be the radius of our circle

#

is that right?

topaz valley Sep 20, 2017, 4:17 AM

#

yes

inner patrol Sep 20, 2017, 4:17 AM

#

😄

#

💡

#

so the total area of a circle is 53,4069cm

topaz valley Sep 20, 2017, 4:19 AM

#

cm^2

#

not cm

inner patrol Sep 20, 2017, 4:20 AM

#

oh yeah

#

I need to type that on my memory sheet

#

the teacher allows us to bring a ''memory sheet''

#

you can hand write exemples on it

#

and things you dont wanna forget

#

and he allows you to bring a sheet with all the formulas on it

#

Well thanks so much for your help and goodnight. Wish me luck for my math test tomorrow 😄 @topaz valley

umbral rivet Sep 20, 2017, 11:16 AM

#

Good luck 👀

quasi mesa Sep 20, 2017, 5:09 PM

#

im not sure if this is geometry but

#

📎 unknown.png

#

i dont know how to work this out haha

dark sparrow Sep 20, 2017, 5:43 PM

#

@quasi mesa you still here?

dark sparrow Sep 20, 2017, 6:24 PM

#

...

umbral rivet Sep 20, 2017, 8:25 PM

#

F

quick mural Sep 20, 2017, 10:21 PM

#

🙄

#

😂

upper karma Sep 21, 2017, 10:39 PM

#

is here anybody into fourier transformation? i am stucked. Cant continue for some reasons.

glacial grail Sep 22, 2017, 5:22 AM

#

How to find fi in these tasks?

#

I have angle a

#

📎 image.jpg

full bough Sep 22, 2017, 5:32 AM

#

=tex 180-\frac{180-\alpha}{2} = \phi

#

._.

charred spearBOT Sep 22, 2017, 5:32 AM

#

📎 latex.png

full bough Sep 22, 2017, 5:33 AM

#

(180 -a)/2 because you will obtain the angle of the isoceles triangle and then to get phi just remember that phi added to angle B will be 180.

#

@glacial grail

glacial grail Sep 22, 2017, 5:35 AM

#

@full bough So it will be this =tex (180 -a)/2

#

Or this =tex 180-\frac{180-\alpha}{2} = \phi

full bough Sep 22, 2017, 5:37 AM

#

Yes.

glacial grail Sep 22, 2017, 5:38 AM

#

First formula or second one?

#

@full bough

full bough Sep 22, 2017, 5:38 AM

#

Second.

glacial grail Sep 22, 2017, 5:38 AM

#

=tex 180-\frac{180-\alpha}{2} = \phi

charred spearBOT Sep 22, 2017, 5:38 AM

#

📎 latex.png

glacial grail Sep 22, 2017, 5:38 AM

#

Ok thanks

full bough Sep 22, 2017, 5:38 AM

#

No problem :3

glacial grail Sep 22, 2017, 5:38 AM

#

For the second it will be same?

full bough Sep 22, 2017, 5:39 AM

#

Do you understand how to get it?

#

And yes.

glacial grail Sep 22, 2017, 5:39 AM

#

How to get what?

full bough Sep 22, 2017, 5:39 AM

#

=tex 180-\frac{180-\alpha}{2} = \phi

charred spearBOT Sep 22, 2017, 5:39 AM

#

📎 latex.png

glacial grail Sep 22, 2017, 5:40 AM

#

to figure out phi I need to know angle of B

#

180-angle(B)

full bough Sep 22, 2017, 5:40 AM

#

Yes.

glacial grail Sep 22, 2017, 5:41 AM

#

But how I can show angle B in this task

full bough Sep 22, 2017, 5:41 AM

#

Just use B.

glacial grail Sep 22, 2017, 5:42 AM

#

I need to make an answer using angle a . So I need to fiugre out B by using a and phi

full bough Sep 22, 2017, 5:43 AM

#

A = B

#

Because it's an isoceles triangle.

#

Which is why I can use 180 = alpha+a+b, and if a = b, then 180 = alpha+2b

glacial grail Sep 22, 2017, 6:13 AM

#

@full bough But how did you figure out that it is isoceles triangle?

#

@full bough by some rule?

full bough Sep 22, 2017, 6:30 AM

#

Yeah. The triangle has one point centered at the center of the circle, and by using law of Sine you'd remember that the angles A and B are equal because the sides are also equal.

glacial grail Sep 22, 2017, 6:39 AM

#

By this rule?

📎 understanding-sine-law-1.png

#

@full bough

full bough Sep 22, 2017, 6:40 AM

#

Yes.

#

@glacial grail basically every point on the edge is equidistant from the center, therefore the two legs extending from the center are of equal length and therefore the opposing angles are also equal.

#

Good night and God bless :3

glacial grail Sep 22, 2017, 6:42 AM

#

@full bough Thanks a lot

sour whale Sep 22, 2017, 5:06 PM

#

hey anyone knowledgeable about isometric viewpoints

jaunty saffron Sep 24, 2017, 4:17 AM

#

from: https://brilliant.org/wiki/section-formula/

📎 Screen_Shot_2017-09-24_at_12.10.29_PM.png

Section Formula | Brilliant Math & Science Wiki

The section formula tells us the coordinates of the point which divides a given line segment into two parts such that their lengths are in the ratio ...

#

is this the right section to ask this

#

anyway um i'm trying to visualize how they got this:

#

📎 Screen_Shot_2017-09-24_at_12.10.19_PM.png

#

can anyone explain why?? because they just say it as "take note that blabla" and i cannot understand how they got this

dark sparrow Sep 24, 2017, 5:17 AM

#

well AP is m units and AB is m+n units

#

so AP/AB = m/(m+n)

#

or equivalently AP = AB * m/(m+n)

shadow geyser Sep 24, 2017, 5:16 PM

#

📎 image.png

#

There is this problem with a rectangular prism, with an open top, and a thickness

#

📎 image.png

#

I'm trying to find the volume needed to make the box and this is what I have

dark sparrow Sep 24, 2017, 5:17 PM

#

there's a simpler way

shadow geyser Sep 24, 2017, 5:17 PM

#

It's not the right answer but idk what else t do

dark sparrow Sep 24, 2017, 5:19 PM

#

📎 IMG_20170924_201902.jpg

#

the picture is meant to be your box but exaggeratedly thick

#

~~thicc~~

#

the volume is the volume of the big box minus its interior

shadow geyser Sep 24, 2017, 5:20 PM

#

Loool

#

Hmm

#

It's right, I just messed up the height part

#

I thought it was -2t before

#

Why is it just -thic

dark sparrow Sep 24, 2017, 5:23 PM

#

well your box has an open top right

shadow geyser Sep 24, 2017, 5:23 PM

#

Yes

dark sparrow Sep 24, 2017, 5:24 PM

#

yeah

#

and like you can see from my drawing that the height of the interior is h-1t

shadow geyser Sep 24, 2017, 5:25 PM

#

Oh I see

#

Thanks so much

jaunty saffron Sep 24, 2017, 10:17 PM

#

thanks too!!

crude kraken Sep 25, 2017, 7:33 PM

#

sin(x^y)=cos(x^y)

#

Trying to solve for y

upper karma Sep 25, 2017, 9:46 PM

#

@crude kraken https://gyazo.com/6c61adbefbca94eb60d19d97f9ac773e

Gyazo

#

i need help with this probability

#

why is the denominator expanded like that

haughty prawn Sep 25, 2017, 10:05 PM

#

the second expression isn't actually equal to the first or third, the third expression is baye's theorem

#

aka the second expression is wrong

#

it should be P(B) in the denominator, or whatever the bottom is called

#

uh wait, why is this in geometry?

#

@upper karma

upper karma Sep 25, 2017, 10:10 PM

#

@haughty prawn please i need your help could i talk with you ill show you the problem

#

https://gyazo.com/9d96b3b7499d81a43176e4098585e02d @haughty prawn

Gyazo

haughty prawn Sep 25, 2017, 10:13 PM

#

bayes theorem 🤷

#

https://upload.wikimedia.org/wikipedia/commons/thumb/7/74/Bayes_theorem_simple_example_tree.svg/220px-Bayes_theorem_simple_example_tree.svg.png like this, but less complicated

#

so you're finding the probability that the email is spam given that it says "free money"

upper karma Sep 25, 2017, 10:19 PM

#

wait this is such dogshit

#

so its not supposed to be p(a) in the denominator?

#

yea

#

acoustic answer smh

upper karma Sep 25, 2017, 11:10 PM

#

Hello! If someone could please help me to get started with this. Sorry its written in finnish, but I can explain anything you need to know. So we need to know alfa(degree) and beta(degree)

📎 724d8c949030478daf6797a0551b0682.png

#

System is balanced. It is supposed to be really easy question, but I am so tilted and tired. And I need to get these done.

dire bronze Sep 25, 2017, 11:42 PM

#

whats the word if the statement,converse,inverse,and contrapostive is true

#

Im helping a friend out in geometry and since I am in algebra 2, I forgot

supple ether Sep 26, 2017, 1:07 AM

#

need help on problem 3

#

📎 image.jpg

#

I don't know how to express things like slope in polar coordinate

upper karma Sep 26, 2017, 1:11 AM

#

Having it upside down doesn't help.

prime junco Sep 26, 2017, 1:16 AM

#

So I've switched to Geometry pre ap and I have a test tomorrow. I know most of the stuff but there's some question I don't even understand it

surreal bolt Sep 26, 2017, 1:17 AM

#

/listening

prime junco Sep 26, 2017, 1:18 AM

#

📎 20170925_201756.jpg

#

📎 20170925_201809.jpg

#

Those are the question I don't even understand

surreal bolt Sep 26, 2017, 1:19 AM

#

12?

prime junco Sep 26, 2017, 1:19 AM

#

What about 12?

surreal bolt Sep 26, 2017, 1:19 AM

#

Hint: Segment Addition postulate

prime junco Sep 26, 2017, 1:20 AM

#

????

#

Like I said @surreal bolt I don't understand lmao

surreal bolt Sep 26, 2017, 1:20 AM

#

If AC is a line segment with B in between A and C ... AB + BC = AC

prime junco Sep 26, 2017, 1:21 AM

#

Ik that the part I'm confused is finding the measures of Xy, yz, and xz

#

XY= x2+3
YZ= x+4
XZ= 49
How am I suppose to find the measurements of the lines???

surreal bolt Sep 26, 2017, 1:22 AM

#

sigh ... XY + YZ = XZ

#

It's a quadratic equation

prime junco Sep 26, 2017, 1:22 AM

#

Doesn't it has to be in order like x2+x+3+4=49?

surreal bolt Sep 26, 2017, 1:24 AM

#

define "be in order"

#

just move everything to one side and factor or use quadratic formula.

prime junco Sep 26, 2017, 1:28 AM

#

Ohh I understand

#

Thx man

surreal bolt Sep 26, 2017, 1:31 AM

#

kk yw

modest locust Sep 26, 2017, 2:30 AM

#

📎 omg.png

#

this typer of question always gets me lol

surreal bolt Sep 26, 2017, 2:31 AM

#

ya add the two smaller angles and set the sum equal to 180

modest locust Sep 26, 2017, 2:32 AM

#

my problem is i didnt set it to 180. Im guessing I just thought of solving angle abc not the entire angle

surreal bolt Sep 26, 2017, 2:33 AM

#

ah. Well... Set It To 180!!

#

😃

modest locust Sep 26, 2017, 2:34 AM

#

so whene ver there is a straight angle both angels will always be 180 for example 6x +40 + 3x +10 = 180

#

where*

surreal bolt Sep 26, 2017, 2:35 AM

#

yup. Have you taken algebra?

modest locust Sep 26, 2017, 2:35 AM

#

i did in high school but forgot im taking albegra on khan academy

#

aswell as geometry

surreal bolt Sep 26, 2017, 2:37 AM

#

well I was going to say the roughest problem you might face here is:
two angles add to 180. The first is x^2 + 30, the other is 2x + 30. What is x?

marsh cipher Sep 26, 2017, 2:40 AM

#

x^2+2x+60=180?

surreal bolt Sep 26, 2017, 2:41 AM

#

yes how would you solve that?

modest locust Sep 26, 2017, 2:45 AM

#

x = 90 lol?

#

probably wrong but i tried lol

marsh cipher Sep 26, 2017, 2:45 AM

#

its 10 and -12

#

i cant do it on paper for some reason

#

oh wait i got it

#

📎 20170925_224816.jpg

surreal bolt Sep 26, 2017, 2:51 AM

#

yup

#

both?

marsh cipher Sep 26, 2017, 2:51 AM

#

yeah

#

but if youre talking about a physical shape, you would ignore the negative one

surreal bolt Sep 26, 2017, 2:52 AM

#

actually the "rule" is plug them back in and make sure that the subbed values are both positive.

#

all angles / lengths etc.

marsh cipher Sep 26, 2017, 2:53 AM

#

i just solved for x, idk what the question was

surreal bolt Sep 26, 2017, 2:53 AM

#

Try this modified question: two angles add to 180. The first is x^2 + 50, the other is 2x + 10. What is x?

modest locust Sep 26, 2017, 2:53 AM

#

is that a 180 or 120 u put lol?

marsh cipher Sep 26, 2017, 2:54 AM

#

i moved the 180 over

#

i just didnt show it

#

@surreal bolt thats the same question

surreal bolt Sep 26, 2017, 2:54 AM

#

nope I disagree 😃

#

Just humor me and try it.

marsh cipher Sep 26, 2017, 2:56 AM

#

📎 20170925_225532.jpg

surreal bolt Sep 26, 2017, 2:56 AM

#

ah ... so 2x + 10 is one of the angles, no? (for the revised problem)

marsh cipher Sep 26, 2017, 2:56 AM

#

yes

surreal bolt Sep 26, 2017, 2:57 AM

#

what happens if x = -12?

marsh cipher Sep 26, 2017, 2:57 AM

#

well then the angle is -14 deg

#

and the othre would be 194

#

so a 180 deg angle

surreal bolt Sep 26, 2017, 2:58 AM

#

yeah unless you are already in Pre-Cal you can't have negative angles. It is a geometry rule you aren't allowed to break yet.

marsh cipher Sep 26, 2017, 2:58 AM

#

so drop the nagative one and use 10

surreal bolt Sep 26, 2017, 2:58 AM

#

10 is fine.

#

There is also a possibility neither answers work. (but you have to have a very mean instructor to get a problem like that)

marsh cipher Sep 26, 2017, 2:59 AM

#

its been a long time since ive taken geometry

#

i dont remember what you can and cant do

surreal bolt Sep 26, 2017, 3:00 AM

#

ah. Yeah no negative angles nor negative lengths.

modest locust Sep 26, 2017, 3:04 AM

#

Thank you for that question I see i need to work even harder to get better at math!

surreal bolt Sep 26, 2017, 3:05 AM

#

yw.

modest locust Sep 26, 2017, 3:05 AM

#

whats the highest level of math you know?

surreal bolt Sep 26, 2017, 3:13 AM

#

me? not much 😃

#

(especially if your definition of "know" means "remember")

marsh cipher Sep 26, 2017, 3:14 AM

#

im in calc 2

modest locust Sep 26, 2017, 3:15 AM

#

i need to get to calculus level as i will be taking computer science next year lol

marsh cipher Sep 26, 2017, 3:15 AM

#

calc 1 is not very hard

#

calc 2 sucks

surreal bolt Sep 26, 2017, 3:15 AM

#

lol are you at Uni?

marsh cipher Sep 26, 2017, 3:15 AM

#

ye

surreal bolt Sep 26, 2017, 3:16 AM

#

yep. In the US calculus is a major "weed out" class in colleges.

modest locust Sep 26, 2017, 3:16 AM

#

i go to work for 8 hours then study for 4-5 so hopefully i do good when i get there lol

surreal bolt Sep 26, 2017, 3:17 AM

#

I had friends like that. Work and study. Dunno how they did it.

modest locust Sep 26, 2017, 3:18 AM

#

well i see how much i hate my fucking job and that motivates me very much lol

surreal bolt Sep 26, 2017, 3:18 AM

#

I didn't have to work much and the college I went to was nice but had low tuition.

thorn talon Sep 26, 2017, 3:19 AM

#

I feel bad for my friends

#

They have to work and study hard for this

#

I don't work and I already feel like I don't have enough time

modest locust Sep 26, 2017, 3:19 AM

#

i dont even know how i could balannce work and school. if possible id rather not work at all when im at school

surreal bolt Sep 26, 2017, 3:21 AM

#

I had a job. But it was like 8-10 hours a week. Oh, and my friend lived at home. I don't even want to imagine a life where you had to make rent and not take out loans.

thorn talon Sep 26, 2017, 3:21 AM

#

I'm already struggling balancing 6 subjects

#

If I had to work

#

I don't know how I would cope

modest locust Sep 26, 2017, 3:21 AM

#

i went to school for music in 2014 and had to work at walmart lol

surreal bolt Sep 26, 2017, 3:22 AM

#

Well one way is to go to a less expensive school. They're out there. Gotta look though.

thorn talon Sep 26, 2017, 3:22 AM

#

My friend has to pay his own tutoring and school fees

#

Which sucks

modest locust Sep 26, 2017, 3:22 AM

#

well im sure i can go for free so thats good

surreal bolt Sep 26, 2017, 3:22 AM

#

ah nice.

#

For the Americans, almost everyone gets a Pell Grant. Good stuff cause it is a grant ("free" money -- no returning it)

thorn talon Sep 26, 2017, 3:23 AM

#

School fees here kind of suck

modest locust Sep 26, 2017, 3:23 AM

#

i owe 5k in loans right now so thats fun

surreal bolt Sep 26, 2017, 3:24 AM

#

ah. Which year are you?

thorn talon Sep 26, 2017, 3:24 AM

#

I have to pay like near 1k a semester

#

Though I do band

surreal bolt Sep 26, 2017, 3:24 AM

#

(we likely shouldn't be using this channel for this discussion but ... not sure I want to talk about my finances in General. 😃 )

thorn talon Sep 26, 2017, 3:24 AM

#

And computer subjects

surreal bolt Sep 26, 2017, 3:25 AM

#

oh nice

thorn talon Sep 26, 2017, 3:25 AM

#

So that's probably why

#

Its still like 500ish without

#

You have to pay fees such as library maintenance

#

Even if you never ever been in the library

modest locust Sep 26, 2017, 3:26 AM

#

wtf?

#

well i lived in a dorm and if some dumbass broke something that belongs tot he school they take it out of each student

surreal bolt Sep 26, 2017, 3:27 AM

#

I have another friend: his family was fairly affluent. His folks didn't help him with finances though. So he got very little funding and had to pay by himself.

thorn talon Sep 26, 2017, 3:28 AM

#

I guess it teaches independence but still sucks

surreal bolt Sep 26, 2017, 3:29 AM

#

I know adults who have a tough time making bills and rent. To need to make money to have a roof, a car, and have time to study at 19? Wow. (his car cost less than his computer though. hehe)

thorn talon Sep 26, 2017, 3:31 AM

#

My laptop is really dead

#

But I don't need a new one like ever

surreal bolt Sep 26, 2017, 3:31 AM

#

anyway I gotta go. :). Laters folks.

thorn talon Sep 26, 2017, 3:31 AM

#

Cya

surreal bolt Sep 26, 2017, 3:31 AM

#

take care.

modest locust Sep 26, 2017, 12:15 PM

#

Hope everyone has a amazing day.

echo void Sep 26, 2017, 4:49 PM

#

Hello everyone.

dark sparrow Sep 26, 2017, 4:52 PM

#

hi

echo void Sep 26, 2017, 4:52 PM

#

Guess everyone is in the general chat huh?

dark sparrow Sep 26, 2017, 4:53 PM

#

if there's a question you'd like to ask, by all means ask it

echo void Sep 26, 2017, 4:54 PM

#

I was trying to get some resource recommendations for Napier's Rules. I'm trying to solve a proof

dark sparrow Sep 26, 2017, 4:54 PM

#

googling gives this http://www.rwgrayprojects.com/rbfnotes/trig/strig/strig.html

echo void Sep 26, 2017, 4:58 PM

#

I've gone through that but I'm having some issues with application deriving how Mason&Dixon found the angle of a star azimuth from zenith while creating the Mason-Dixon line.

📎 clip_image001.png

#

It's 89 55 51 in the image

#

I sketched a picture with the known variables and a Naiper's wheel...

📎 unknown.png

#

Based from this I used the principle that "sin mid part = tan of adj part" or "sin mid part = cos of opp part" .... which gave me "sin-co A = (tan EA) / (tan PA)"

glacial grail Sep 26, 2017, 6:10 PM

#

@quick mural hey can you help me?

#

📎 image.jpg

echo void Sep 26, 2017, 6:16 PM

#

@glacial grail what are you trying to solve for?

upper karma Sep 26, 2017, 6:18 PM

#

^

#

📎 Screenshot_2017-05-28-13-10-15.png

#

Apparently this is the hardest math problem on the SAT

glacial grail Sep 26, 2017, 6:22 PM

#

@echo void find the derivative of the function y=f(x) at the point x0

#

I need to figure out slope angle

echo void Sep 26, 2017, 6:24 PM

#

@glacial grail I see in your sketch that F(x) appears curved. Is that a constraint of the problem?

glacial grail Sep 26, 2017, 6:27 PM

#

@echo void I need to figure out this angles

#

📎 Inkedimage_LI.jpg

#

tan of these

echo void Sep 26, 2017, 6:34 PM

#

For number 1: Use the give angle of 150 degrees to solve for its complementary angle on the other side of x sub o. Then solve the internal angles of the right triangle. Then use those angels to solve for your angle marked in red.

#

@glacial grail

📎 unknown.png

upper karma Sep 26, 2017, 6:36 PM

#

for the SAT problem, wouldn't it be (area of 1/4th of circle with r = 6 - area of white triangle ) or just (3pi - 14) ?

echo void Sep 26, 2017, 6:36 PM

#

@glacial grail you can use a similiar principle to solve for your second problem

glacial grail Sep 26, 2017, 6:37 PM

#

@echo void Tha broblem is in your image the 150 sticks to triangle but in mine it to x0

echo void Sep 26, 2017, 6:42 PM

#

@glacial grail My triangle is based off your sketch. Maybe this will help more....

📎 unknown.png

glacial grail Sep 26, 2017, 6:43 PM

#

@echo void I see thanks a lot.

echo void Sep 26, 2017, 6:43 PM

#

@glacial grail No problem

upper karma Sep 26, 2017, 6:44 PM

#

hey ann @dark sparrow for the SAT problem posted above, wouldn't it be (area of 1/4th of circle with r = 6 - area of white triangle ) or just (3pi - 14) ?

echo void Sep 26, 2017, 6:46 PM

#

I take it that no one active in this group is familiar with euclidean geometry? XD

upper karma Sep 26, 2017, 6:47 PM

#

you should post the question anyways someone is bound to solve it eventually

echo void Sep 26, 2017, 6:48 PM

#

I have some images above.

dark sparrow Sep 26, 2017, 6:48 PM

#

i'd help but i'm trying to be active in n different places at once

#

with n > 3

echo void Sep 26, 2017, 6:48 PM

#

I'm also here to help. I like lending a hand when and where I can. In highschool geometry was difficult for me, so I make it a point to help

upper karma Sep 26, 2017, 6:49 PM

#

scain you see the SAT problem listed above right

#

shouldn't it be 3pi - 14

dark sparrow Sep 26, 2017, 6:49 PM

#

nope

#

3π + 10 is the answer i arrived at

upper karma Sep 26, 2017, 6:50 PM

#

3pi would be the 1/4th of the circle right

#

me too in a very handwavy way

#

I expected 3pi +10

dark sparrow Sep 26, 2017, 6:50 PM

#

📎 unknown.png

upper karma Sep 26, 2017, 6:51 PM

#

i see

#

but 3pi is not the entire 1/4th of the region then?

dark sparrow Sep 26, 2017, 6:52 PM

#

3π is the length of that one arc

upper karma Sep 26, 2017, 6:52 PM

#

hm

#

i thought it would be the entire region since 1/4 (2 * pi * r ), r being 6 in this case

#

resulted in 3pi for the perimeter

dark sparrow Sep 26, 2017, 6:53 PM

#

no

#

1/4 * 2πr is the quarter circle bit

upper karma Sep 26, 2017, 6:57 PM

#

right right i see now

#

i am still a tad unsure of how 10 comes to place

#

i see that 6 is the hypotenuse of the triangle

#

6 is the only non trivial one to get no ?

#

and i feel that the other 4 result from SA and CT

dark sparrow Sep 26, 2017, 6:59 PM

#

that's correct

upper karma Sep 26, 2017, 7:00 PM

#

my question is how is it split into SA and CT

#

im afraid i cant make that connection on the lengths

dark sparrow Sep 26, 2017, 7:00 PM

#

you don't need to get SA and CT by themselves

#

SA + CT = (SR+RT) - (AR+RC)

upper karma Sep 26, 2017, 7:01 PM

#

oohh you just do 12 - 8

dark sparrow Sep 26, 2017, 7:01 PM

#

precisely

upper karma Sep 26, 2017, 7:01 PM

#

and add it to the hyp of the triangle for the rest of the outline

dark sparrow Sep 26, 2017, 7:01 PM

#

yes

upper karma Sep 26, 2017, 7:01 PM

#

cool, thanks for the explanation

#

AC=6 because AC=BR= radius=6
SBT = quarter circle r=6 = 3Pi
and lets saythat RA + RC = 8 but RS +RT = 12 so our two unknown pieces add up (12-8)=4

so the perimeter is 6+4+3pi= 10+3pi

dark sparrow Sep 26, 2017, 7:06 PM

#

correct, but you're a bit late xP

upper karma Sep 26, 2017, 7:07 PM

#

Lil

#

Lol

#

how old are you when you take the SAT ?

#

Im taking it this year

#

And im 16

#

and this was the longest thing you could have on that

#

okay

upper karma Sep 26, 2017, 7:51 PM

#

if i can add some context to it theres a large majority of students in the US system (including myself at the time) that are led by the wrong example of being taught shortcuts/ways to memorize problems and to operate with no logical reasoning whatsoever, I have found interest in math at age 19 but i had to revisit more basic concepts that I, along with other students, had "skipped through"

#

imo the importance and use of math in daily life even is not reflected upon students at times, so these have to come back to "older" more basic concepts to fully understand them

#

please do note though that i am not blaming the system for the lack of practice time and desire to understand since that ultimately falls on the student anyways, but some educators could use some improving

#

this problem doesnt exist only in the us

crude kraken Sep 27, 2017, 1:29 AM

#

Does anyone have a graph for a circle where as n increases, the circle gets wider, but if n is smaller than the distance between the previous whole number n and the next is smaller than if n is larger? This is what I have right now but it's evenly spaced. Un-squaring s gets the effect I want but reversed where the spacing gets smaller as n (in this case s) increases.

📎 unknown.png

#

Nvm, I'm stupid, just have to turn s^2 into 2^s

#

But now there's no way to have the center at zero, question stands

#

Okay I'm stupid still, just have to add a -1 to the end.

umbral rivet Sep 27, 2017, 2:55 AM

#

👍

surreal bolt Sep 27, 2017, 8:41 AM

#

the angle measure is 120. @scain2004#0398

upper karma Sep 27, 2017, 6:23 PM

#

Can someone explain me why the length of the two vectors a and b are the same here?

Suppose that a=r*b, r>=0.

||a||+||b|| = ||a+b||.

#

wouldnt it be enough to know that all 3 points in b are positive?

dark sparrow Sep 27, 2017, 6:24 PM

#

what do you mean by "all three points in b are positive"?

upper karma Sep 27, 2017, 6:25 PM

#

sorry, i just translated it from german. i mean the coordinates

dark sparrow Sep 27, 2017, 6:25 PM

#

this is a fact that is independent of what coordinate system you choose

#

so saying anything about the signs of coordinates of b is a moot point

upper karma Sep 27, 2017, 6:26 PM

#

I see, then why is the statement right?
||a||+||b|| = ||a+b||.

#

only in the case of a=r*b with r>=0

dark sparrow Sep 27, 2017, 6:27 PM

#

a and b are parallel

#

hell they even point in the same direction

#

a + b = (r+1)b

upper karma Sep 27, 2017, 6:28 PM

#

So a and b need to be parallel in order for this statement to be right?

#

and thus a=r*b with r>=0?

dark sparrow Sep 27, 2017, 6:34 PM

#

well, yes

upper karma Sep 27, 2017, 6:43 PM

#

and why is that?

dark sparrow Sep 27, 2017, 6:46 PM

#

is it not obvious geometrically?

upper karma Sep 27, 2017, 6:47 PM

#

Its like the Triangle inequality right?

dark sparrow Sep 27, 2017, 6:48 PM

#

this is a degenerate triangle, if anything

lusty sparrow Sep 27, 2017, 9:09 PM

#

Why/how do you get a decimal from distance formula? For example, if you get radical 10 from doing distance formula and the question asks you to round to the nearest tenth, then how do you convert it to a decimal?

crude kraken Sep 27, 2017, 9:14 PM

#

Ideally you would want to use a calculator and just round

dark sparrow Sep 28, 2017, 5:03 AM

#

yeah, that

#

there is, however, an algorithm for calculating square roots on paper

lean estuary Sep 28, 2017, 1:14 PM

#

Guys help with trigonometric identities

#

How do i prove this >.>

#

📎 image.jpg

#

Which identities should i use

dark sparrow Sep 28, 2017, 1:19 PM

#

one way would be to rewrite tan(θ) as sin(θ)/cos(θ)

#

so your lefthand side becomes

#

=tex \cos(\theta) + \frac{\sin^2(\theta)}{\cos(\theta)}

charred spearBOT Sep 28, 2017, 1:19 PM

#

📎 latex.png

dark sparrow Sep 28, 2017, 1:20 PM

#

which can also be rewritten as

#

=tex \frac{\cos^2(\theta)}{\cos(\theta)} + \frac{\sin^2(\theta)}{\cos(\theta)}

charred spearBOT Sep 28, 2017, 1:20 PM

#

📎 latex.png

dark sparrow Sep 28, 2017, 1:21 PM

#

do i need to explain what comes next?

#

@lean estuary

lean estuary Sep 28, 2017, 1:21 PM

#

Wait

#

How did the left side turn into cos^2 / cos

dark sparrow Sep 28, 2017, 1:23 PM

#

... x = x^2/x

#

i multiplied and divided the left bit by cos(θ)

lean estuary Sep 28, 2017, 1:23 PM

#

Oh okay

dark sparrow Sep 28, 2017, 1:24 PM

#

really this is less using identities and more just

#

moving around algebraic furniture

#

which is a lovely word that i saw someone on here say a few times

lean estuary Sep 28, 2017, 1:24 PM

#

Well you already know my algebra is pretty bad 😂

dark sparrow Sep 28, 2017, 1:24 PM

#

doesn't mean you can't/shouldn't review it

lean estuary Sep 28, 2017, 1:25 PM

#

multiplying and dividing the left side with cos o
Never even came to my mind >.>

dark sparrow Sep 28, 2017, 1:26 PM

#

that's a theta

#

not an o

lean estuary Sep 28, 2017, 1:26 PM

#

Yeah

dark sparrow Sep 28, 2017, 1:26 PM

#

and i mean, what i had in mind is rewriting the left hand side as one fraction

lean estuary Sep 28, 2017, 1:26 PM

#

I know for it to be equal i need to achieve 1/cos theta

dark sparrow Sep 28, 2017, 1:28 PM

#

that is true, albeit badly worded

lean estuary Sep 28, 2017, 1:29 PM

#

Do i convert the left side cos squared theta to 1- sin^2

dark sparrow Sep 28, 2017, 1:29 PM

#

why not just add the two fractions together?

#

you're kinda overcomplicating here

#

i mean you can do it but it's a bit of a detour in terms of algebraic moves

lean estuary Sep 28, 2017, 1:30 PM

#

So cos squared theta + sin theta / 2cos theta

dark sparrow Sep 28, 2017, 1:30 PM

#

...

#

that's sin**^2**(θ) you had there
PARENTHESES!

#

where'd you get that 2 multiplier?

main sluice Sep 28, 2017, 1:31 PM

#

this isn't geometry

lean estuary Sep 28, 2017, 1:32 PM

#

Woops
So no imaginary 1 next to cos >.<

dark sparrow Sep 28, 2017, 1:32 PM

#

sky posted his original question here and i couldn't give less of a shit right now

#

So no imaginary 1 next to cos >.<
huh?

lean estuary Sep 28, 2017, 1:32 PM

#

I thought cos+cos 2cos

dark sparrow Sep 28, 2017, 1:32 PM

#

yes, but does a/c + b/c equal (a+b)/(2c)?

#

according to you, 2/3 + 1/3 = 3/6

lean estuary Sep 28, 2017, 1:32 PM

#

And cos x cos = cos^2

#

Ohh

#

Yeah that was dumb

main sluice Sep 28, 2017, 1:33 PM

#

ahh

#

the linear bias

dark sparrow Sep 28, 2017, 1:33 PM

#

cos(θ) isn't any different than any other algebraic object in this respect, and @main sluice you're being a bit obstructive right now

main sluice Sep 28, 2017, 1:33 PM

#

fine I'll take this to the trash

lean estuary Sep 28, 2017, 1:34 PM

#

So cos^2 (theta) + sin ^2 (theta) / cos(theta)

dark sparrow Sep 28, 2017, 1:34 PM

#

parentheses!

#

(cos^2(θ) + sin^2(θ))/cos(θ)

lean estuary Sep 28, 2017, 1:35 PM

#

Right

dark sparrow Sep 28, 2017, 1:35 PM

#

i hope the next step is obvious

lean estuary Sep 28, 2017, 1:36 PM

#

The numerator is equal to 1

#

Yay i got it

dark sparrow Sep 28, 2017, 1:36 PM

#

👏

lean estuary Sep 28, 2017, 1:36 PM

#

Thanks @dark sparrow

dark sparrow Sep 28, 2017, 1:36 PM

#

once again tho

#

you really need to give your algebra skills a solid review

lean estuary Sep 28, 2017, 1:38 PM

#

Where do i start

dark sparrow Sep 28, 2017, 1:39 PM

#

what do you mean?

#

do you want me to link you to a resource or do you want me to say what part of algebra it seems to me you're lacking in?

#

if it's the former, khanacademy

#

if it's the latter, you seem to have trouble manipulating algebraic fractions

upper karma Sep 28, 2017, 1:45 PM

#

ann it would be helpful if you could share a book/pdf to a college algebra book too if possible

#

may look into it when im done with my semester just to make sure im good with algebra

dark sparrow Sep 28, 2017, 1:46 PM

#

don't really have any books on the radar atm sorry

lean estuary Sep 28, 2017, 1:47 PM

#

Was the question earlier supposed to be in the algebra channel?

dark sparrow Sep 28, 2017, 1:49 PM

#

idk, we don't really have a dedicated trig channel so it's a bit of a complicated situation

lean estuary Sep 28, 2017, 1:52 PM

#

So i have another question with phi on it

#

Or like the vertical theta

#

Not sure how you spell it

dark sparrow Sep 28, 2017, 1:53 PM

#

=tex \varphi

charred spearBOT Sep 28, 2017, 1:53 PM

#

📎 latex.png

dark sparrow Sep 28, 2017, 1:53 PM

#

this?

#

that letter is called phi

#

it's sometimes written $$ \phi $$ as well though

charred spearBOT Sep 28, 2017, 1:53 PM

#

📎 latex.png

crude kraken Sep 28, 2017, 1:54 PM

#

Handwriting preference.

#

Isn't it also the F in Russian?

dark sparrow Sep 28, 2017, 1:54 PM

#

i prefer the former since the latter looks too much like a russian letter pronounced the same

#

yep

lean estuary Sep 28, 2017, 1:54 PM

#

Yeah that

#

Our book has the latter

#

📎 image.jpg

#

But like for number 6

dark sparrow Sep 28, 2017, 1:55 PM

#

honestly φ is just a letter

#

nothing special at all about it

lean estuary Sep 28, 2017, 1:55 PM

#

I kind of got the right side already or the tan phi

#

📎 image.jpg

#

But how do i get the cot theta from the left side

dark sparrow Sep 28, 2017, 1:55 PM

#

you can cancel out cos(φ)

lean estuary Sep 28, 2017, 1:55 PM

#

Either that or im completely wrong

dark sparrow Sep 28, 2017, 1:55 PM

#

and be left with cos(θ)/sin(θ)

#

which is cot(θ) by definition

lean estuary Sep 28, 2017, 1:56 PM

#

.... Im so dumb im sorry

#

I was looking at 1/ tan

dark sparrow Sep 28, 2017, 1:56 PM

#

1/tan and cot are the same thing lol

lean estuary Sep 28, 2017, 1:56 PM

#

How do you type so fast with the symbols theta

#

Yeah i know

dark sparrow Sep 28, 2017, 1:57 PM

#

i have an autohotkey script set up so that i can type the whole greek alphabet with ease

lean estuary Sep 28, 2017, 1:57 PM

#

On mobile?

dark sparrow Sep 28, 2017, 1:57 PM

#

no

#

on pc

#

on mobile i just have greek enabled as one of the languages on my keyboard app

#

btw it wouldn't hurt to make a little cheat sheet with the greek alphabet and put it somewhere you can access it easily

#

since greek letters are pretty common in math

#

anyway on pc it actually takes me more time to type a greek letter than on mobile lol

#

3 keystrokes, due to the way i set my script up

umbral rivet Sep 28, 2017, 3:53 PM

#

👀

dark sparrow Sep 28, 2017, 3:54 PM

#

👀

#

i can drop the part of the AHK script that's responsible for greek letters in #chill if you want

umbral rivet Sep 28, 2017, 3:55 PM

#

Ooh

vale raven Sep 28, 2017, 3:55 PM

#

I used to have a keyboard layout where

umbral rivet Sep 28, 2017, 3:55 PM

#

A, h, k

#

That's um

vale raven Sep 28, 2017, 3:55 PM

#

caps lock turned on greek mode

umbral rivet Sep 28, 2017, 3:55 PM

#

Vertex form

#

👏

dark sparrow Sep 28, 2017, 3:55 PM

#

the letters commonly used in the vertex form template

umbral rivet Sep 28, 2017, 3:55 PM

#

:)

dark sparrow Sep 28, 2017, 3:55 PM

#

also i think h and k are common for the coordinates of a fixed point

#

like the template for a circle's eq is commonly given as (x-h)^2 + (y-k)^2 = r^2

#

though ofc it could be given just as easily as (x-a)^2 + (y-b)^2 = r^2; the letters used don't matter

umbral rivet Sep 28, 2017, 4:04 PM

#

;o

violet hornet Sep 28, 2017, 7:38 PM

#

Hello

#

I have a question about sin sin-1 etc..

#

Not sure how to phrase it

violet hornet Sep 28, 2017, 8:00 PM

#

if I have 4=cos(a)

#

how do I solve for a?

#

nvm I messed up

#

brb

#

if I had 19/20 = cos(a) how do I solve for a

upper karma Sep 28, 2017, 8:13 PM

#

put into calculator

#

arccos(19/20)

#

you have to arccos both sides

#

arccos(cos(a))=arccos(19/20)

#

@violet hornet

#

a=arccos(19/20)

dark sparrow Sep 28, 2017, 8:25 PM

#

are there any restrictions on a?

#

bc if not

#

a = ± arccos(19/20) + 2πk is a solution for all k in Z

upper karma Sep 28, 2017, 8:27 PM

#

its probably from a triangle

dark sparrow Sep 28, 2017, 8:28 PM

#

if it's from a triangle, then yeah the only solution would be arccos(19/20)

chilly prism Sep 29, 2017, 1:11 AM

#

@fallen ivy can you hlep me

fallen ivy Sep 29, 2017, 1:28 AM

#

Busy

daring crag Sep 29, 2017, 4:02 AM

#

can someone help D:

📎 Screen_Shot_2017-09-28_at_8.47.42_PM.png

covert idol Sep 29, 2017, 4:03 AM

#

supplementary angles add up to 180

#

and then just need the formula for angle sum of an n sided polygon

daring crag Sep 29, 2017, 4:04 AM

#

Overall, 720.

#

What do i do from there...

#

Im so confused.....

covert idol Sep 29, 2017, 4:06 AM

#

well if the angle sum is 720

#

and there are 6 angles

#

then each angle would be...?

daring crag Sep 29, 2017, 4:06 AM

#

720/6

covert idol Sep 29, 2017, 4:06 AM

#

==720/6

charred spearBOT Sep 29, 2017, 4:06 AM

#

120

covert idol Sep 29, 2017, 4:06 AM

#

yup

daring crag Sep 29, 2017, 4:07 AM

#

welcome to 2017

📎 Screen_Shot_2017-09-28_at_9.06.45_PM.png

covert idol Sep 29, 2017, 4:07 AM

#

no

#

z is not 120

eager pendant Sep 29, 2017, 4:07 AM

#

two angles in a line add to 180

covert idol Sep 29, 2017, 4:07 AM

#

each interior angle is 120

eager pendant Sep 29, 2017, 4:07 AM

#

so z=180-120=?

covert idol Sep 29, 2017, 4:07 AM

#

^

daring crag Sep 29, 2017, 4:07 AM

#

oh

covert idol Sep 29, 2017, 4:07 AM

#

supplementary angles (angles in a straight line) add up to 180, so if one side is 120

#

the other side is 180-120

daring crag Sep 29, 2017, 4:08 AM

#

can you help me with more

upper karma Sep 29, 2017, 4:08 AM

#

maybe

covert idol Sep 29, 2017, 4:09 AM

#

post away

eager pendant Sep 29, 2017, 4:09 AM

#

dont ask to ask, just ask

daring crag Sep 29, 2017, 4:09 AM

#

📎 Screen_Shot_2017-09-28_at_8.43.33_PM.png

eager pendant Sep 29, 2017, 4:09 AM

#

so you know that two angles on a line add to 180*, right?

daring crag Sep 29, 2017, 4:09 AM

#

S (n-2) * 180

#

mhm

eager pendant Sep 29, 2017, 4:10 AM

#

so what would the angle inside the triangle (next to 135*) be equal to?

#

what would the red angle be equal to, if two angles on a line add to 180*?

📎 unknown.png

daring crag Sep 29, 2017, 4:11 AM

#

45?

eager pendant Sep 29, 2017, 4:11 AM

#

yep!

#

and what would the blue be

daring crag Sep 29, 2017, 4:11 AM

#

180-45??

#

Im so lost

eager pendant Sep 29, 2017, 4:12 AM

#

how did you get the angle for the red

#

what did you calculate

daring crag Sep 29, 2017, 4:12 AM

#

180-135

eager pendant Sep 29, 2017, 4:12 AM

#

yep - because the red angle and 135* are on a straight line, they both add to 180

#

so the red angle is equal to 180-135

#

now apply the same reasoning to the blue

daring crag Sep 29, 2017, 4:13 AM

#

80

eager pendant Sep 29, 2017, 4:13 AM

#

absolutely right

#

i'll skip the external angle theorem (if you know that, you could apply it)

#

so you have two angles of the inside triangle

#

45 and 80

#

so what would the third angle be?

daring crag Sep 29, 2017, 4:14 AM

#

180-125?

eager pendant Sep 29, 2017, 4:14 AM

#

the pink angle

📎 unknown.png

#

yep - what does that come to?

daring crag Sep 29, 2017, 4:14 AM

#

==180-125

charred spearBOT Sep 29, 2017, 4:14 AM

#

55

eager pendant Sep 29, 2017, 4:14 AM

#

so that angle and y* are on a straight line

#

can you go from there/

daring crag Sep 29, 2017, 4:17 AM

#

Ohh, i got it.

#

And i got another one lol

#

📎 Screen_Shot_2017-09-28_at_8.47.19_PM.png

eager pendant Sep 29, 2017, 4:20 AM

#

do you know the formula for the sum of interior angles for an n-sided polygon

daring crag Sep 29, 2017, 4:21 AM

#

6-4=2*180

#

360?

eager pendant Sep 29, 2017, 4:22 AM

#

thats not the formula, though you're close

#

=tex 180\times(n-2)

charred spearBOT Sep 29, 2017, 4:22 AM

#

📎 latex.png

daring crag Sep 29, 2017, 4:22 AM

#

ack

eager pendant Sep 29, 2017, 4:22 AM

#

and as for being distracted, i recommend you try and avoid that (e.g. by sitting away)

#

i know that feels bad, etc. but its up to you to decide your priorities

#

so we have n=6

#

so our angle sum is $180\times4=720$

#

180*4=720

#

so all the angles in the polygon add to 720

#

so we have

#

=tex 60+120+100+65+3x=720

charred spearBOT Sep 29, 2017, 4:24 AM

#

📎 latex.png

eager pendant Sep 29, 2017, 4:24 AM

#

can you go fromr there?

daring crag Sep 29, 2017, 4:24 AM

#

ill try

#

thanks

eager pendant Sep 29, 2017, 4:24 AM

#

tell me if you need more help

daring crag Sep 29, 2017, 4:24 AM

#

Mhm

#

@eager pendant Im stuck again..

#

i got one answer..

dark sparrow Sep 29, 2017, 4:36 AM

#

where are you stuck?

daring crag Sep 29, 2017, 4:36 AM

#

Ive got the value of 125 for x, but now i need 2x..

eager pendant Sep 29, 2017, 4:37 AM

#

=tex 2x=2\timesx

charred spearBOT Sep 29, 2017, 4:37 AM

#

📎 latex.png

eager pendant Sep 29, 2017, 4:37 AM

#

that came out wrong

daring crag Sep 29, 2017, 4:37 AM

#

lol

dark sparrow Sep 29, 2017, 4:37 AM

#

well if x = 125, 2 * x = ?

daring crag Sep 29, 2017, 4:37 AM

#

Thats what im trying to get, but im confused..

#

oh

#

jesus im dumb..

upper karma Sep 29, 2017, 12:55 PM

#

250 😃

cunning valley Sep 29, 2017, 2:54 PM

#

Wow youre a genius

upper karma Sep 29, 2017, 2:59 PM

#

you're 😛

west dune Sep 29, 2017, 3:16 PM

#

Lmao

tropic island Sep 29, 2017, 8:46 PM

#

hi

past mantle Sep 30, 2017, 5:23 PM

#

i have a question about this

#

📎 Line.PNG

#

if anyone can help me

quasi lion Sep 30, 2017, 5:24 PM

#

horizontal

dark sparrow Sep 30, 2017, 5:24 PM

#

what have you tried so far?

quasi lion Sep 30, 2017, 5:25 PM

#

It means it's the line that looks like the horizon

dark sparrow Sep 30, 2017, 5:25 PM

#

do you know what a horizontal line is?

quasi lion Sep 30, 2017, 5:25 PM

#

It means it doesn't increase nor decreases

past mantle Sep 30, 2017, 5:25 PM

#

yes

#

x = undefined?

dark sparrow Sep 30, 2017, 5:25 PM

#

no

quasi lion Sep 30, 2017, 5:25 PM

#

So the coefficient before x is 0 (no increase nor decrease)

past mantle Sep 30, 2017, 5:25 PM

#

oh

quasi lion Sep 30, 2017, 5:25 PM

#

y = 0*x + b = b

#

In (2,3)

#

3 = y= 0*2 + b

#

b=3

past mantle Sep 30, 2017, 5:26 PM

#

ok

dark sparrow Sep 30, 2017, 5:28 PM

#

y = constant is what horizontal lines' equations look like

#

x = constant for vertical lines

past mantle Sep 30, 2017, 5:29 PM

#

ok

#

now i understand

plucky perch Sep 30, 2017, 10:14 PM

#

For 3 non-collinear points, there is exactly one plane

#

Can someone give me a better explanation of this?

#

My textbook had a tripod.

quasi lion Sep 30, 2017, 10:16 PM

#

There is only one plane that goes through (3 points that aren't in a single line)

plucky perch Sep 30, 2017, 10:18 PM

#

ah

#

I see

#

sortve how only 1 line goes through 2 points

quasi lion Sep 30, 2017, 10:18 PM

#

ye

dense holly Sep 30, 2017, 10:19 PM

#

as an exercise, try to come up with two different planes that go through the same three points

#

📎 plane.png

surreal bolt Oct 1, 2017, 8:22 AM

#

um ... what is the geometry?

dark sparrow Oct 1, 2017, 8:32 AM

#

Euclidean

soft anvil Oct 1, 2017, 9:38 AM

#

this is probably a bad question to ask, but can the planes have the same equation

dark sparrow Oct 1, 2017, 9:39 AM

#

what planes?

soft anvil Oct 1, 2017, 9:41 AM

#

oh nvm

dense holly Oct 1, 2017, 2:31 PM

#

(excercise was for mrphp, sorry for confuse)

tropic island Oct 1, 2017, 4:15 PM

#

A pedestrian left his house and started walking on a straight street, resting at times as necessary. The graph below shows the distance he covered as a function of time. Find the formula describing how his speed depends on the time, and graph this function.

#

📎 Geo.png

#

If the speed marked as S, then :
S = , when < t <
S = , when ≤ t <
S = , when ≤ t <
S =, when≤ t <
S =, when ≤ t <_
Note : List your answers according to the intervals of t (from left to right).

upper karma Oct 1, 2017, 4:18 PM

#

@tropic island 12

dense holly Oct 1, 2017, 4:56 PM

#

@tropic island what have you tried so far?

dark sparrow Oct 1, 2017, 5:27 PM

#

they seem to be offline

bleak rivet Oct 1, 2017, 7:22 PM

#

📎 34.PNG

dark sparrow Oct 1, 2017, 7:23 PM

#

what have you tried so far?

bleak rivet Oct 1, 2017, 7:23 PM

#

so far

#

((2x+15)*(2x+17))-255

dark sparrow Oct 1, 2017, 7:24 PM

#

yes

#

are you able to expand that?

bleak rivet Oct 1, 2017, 7:24 PM

#

yeah

dark sparrow Oct 1, 2017, 7:24 PM

#

what do you get?

bleak rivet Oct 1, 2017, 7:24 PM

#

it comes out to 4x^2+66x

dark sparrow Oct 1, 2017, 7:25 PM

#

are you sure that's 66 you have there?

#

and not 2 * 15 + 2 * 17, which would be 64

bleak rivet Oct 1, 2017, 7:25 PM

#

so it would be 64

#

ahh

#

so the answer is D

dark sparrow Oct 1, 2017, 7:27 PM

#

yes

eager pendant Oct 2, 2017, 3:05 AM

#

is that typeset in word?

covert idol Oct 2, 2017, 5:53 AM

#

m is fine

bleak rivet Oct 2, 2017, 5:36 PM

#

This would be 46 right? cause Angle RPA = Angle X?

📎 49.PNG

fresh quiver Oct 2, 2017, 5:39 PM

#

No, that's not true. AB is parallel to PR, so angle RPA= angle BAQ.

bleak rivet Oct 2, 2017, 5:41 PM

#

mmmm Right

#

so

#

Angle BQA = 47

#

But I dont BAQ or QBA

#

so how would I find one of the two of those?

#

OHHH

#

wait

#

so Angle RPQ = 46

#

and BA is parallel

#

so BAQ = 46 as well

#

so x still = 46

fresh quiver Oct 2, 2017, 5:44 PM

#

No, PQ is not parallel to RQ. From what you're saying, you're taking angle x and angle BAQ to be alternate interior angles, which is clearly not true as these two lines meet.

#

You know angle BQA and angle BAQ, so you can find QBA

bleak rivet Oct 2, 2017, 5:45 PM

#

I dont know angle BAQ

#

Unless angle BAQ = RPQ

fresh quiver Oct 2, 2017, 5:46 PM

#

so BAQ = 46 as well

#

You typed this

bleak rivet Oct 2, 2017, 5:46 PM

#

Well thats my question