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empty mason
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it would be less clean i think

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from here, because idk all my summation formulas by heart, let us call z^1+z^3+...+z^13=S which we want to find a closed form for S. Notice that when multiplying S by z^2, it is the same as S but taking away the z^1 and adding the z^15. We can rewrite this into an equation as z^2(S)=S-z^1+z^15, S(z^2-1)=z^15-z^1 in which S=(z^15-z^1)/(z^2-1) in which we have found the closed form for S

rapid gate
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ok lemme expand it term by term

empty mason
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ok

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alpine sable
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Im trying to figure out a formula to calculate the time needed between each letter in a 4 letter word to satisfy an inputted int wpm

alpine sable
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so say I input the number 60

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it should know that i should need 0.25 seconds between each letter to type 1 word every second

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that 0.25 input is the number I need as output

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i input wpm, output is time between letters needed in 4 letter word

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the time between each letter should be bigger the lower the wpm and vice versa

exotic canopy
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60 wpm is 1 wps

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so just do wps/4

alpine sable
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true true I thought og that

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but how do I figure out the wps?

exotic canopy
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divide by 60

alpine sable
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but then the time between each letter would be bigger the higher the wpm

exotic canopy
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complete formula is wpm/(60*4)

alpine sable
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Ohhh times 4

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not /4

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wow

alpine sable
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hmmm

exotic canopy
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my bad

alpine sable
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nono its fine

exotic canopy
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1/(wps*4) like this yeah

alpine sable
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how do I figure out the wps??

exotic canopy
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divide wpm by 60

alpine sable
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I see I see!

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wow this is complicated xD

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ill test it one sec

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THIS IS AMAZING

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it works!!!

exotic canopy
alpine sable
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it was for me xD

exotic canopy
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completely simplified it is $\frac{15}{wpm}$ if you need to implement it as code or something

ocean sealBOT
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artemetra

alpine sable
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Im so happy

exotic canopy
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where 15 is because of 60/4

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always welcome!

alpine sable
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thank you so much

alpine sable
exotic canopy
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generalized is $\frac{\frac{60}{n}}{wpm}$

ocean sealBOT
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artemetra

exotic canopy
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where n is the length of a word

alpine sable
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its better less simplified cause I can edit the avg letter per word

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depending on the sentence inputted

exotic canopy
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okay okay

alpine sable
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yesyes

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stay safe

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byebye

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.close

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alpine sable
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I appreciate it

lone heartBOT
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cyan sable
#

I dont understand the math used in the solution of an electrical engineering assignment

median oar
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can you show us?

cyan sable
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Yes one moment, let me pull it up

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Here it is

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I dont understand why its ((1,5)^2)/(1^2)

edgy ingot
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!original

lone heartBOT
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Please show the original problem, exactly as it was stated to you, with the entire original context. A picture or screenshot is best. If the original problem is not in English, then post it anyway! The additional context might still be helpful. Do your best to provide a translation.

cyan sable
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One second

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So its about a diode with the capacity of 47pF

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And a forward voltage of 0.8V

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The goal is to to choose the capacitance and inductance, so that it resonates on two frequencies

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10MHz and 15MHz

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If no voltage is applied on the diode, its own (default) capacitance is 47pF, but when 10V is applied it, it changes to 12.8pF according to the calculation

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So we have two different total capacitances depending on whether direct current is on the diode or not

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I understand whats going on, but i just dont see why the prof has calculated it that way in the circle

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trim summit
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Can anyone please explain to me what does the dash symbol ' mean?

trim summit
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right after 47

coral flower
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Minutes i think

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1/60 degree

trim summit
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huh

coral flower
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Like 1 hr 47 min
That's another unit

trim summit
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how is that trigonometry tho

coral flower
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It's a further divided unit of degree

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1/60 degree = 1minute

trim summit
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how would i put it into the calculator

coral flower
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47 minute is 47/60 degrees

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So angle A is
101 * 47/60 degrees

trim summit
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is it always going to be /60?

coral flower
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Yes

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Btw if there are 2 dashes

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Like ''

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That's 1second

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Further division of minute

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1 second = 1/60 minute
1 minute = 1/60 degree

trim summit
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so it would be /360?

coral flower
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3600, yes

trim summit
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ohhh okayy

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tysm

coral flower
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Np

trim summit
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damn thats weird

coral flower
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Ik

trim summit
#

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misty nebula
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ok so

lone heartBOT
misty nebula
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to know if the matrix is regular or not

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it shld have all slots non zero number

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and if not i shld check for like

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i have matrix T

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if it has zero in it

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i shld check for T^2

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if it still got zero

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i shld check for T^3

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and so on

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until i find a T that has all numbers non zero

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if i didnt find that then its not regular

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thats what i found on yt

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but my teacher said otherwise

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if for example

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A belongs to M7_R

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i shld have B belongs to M7_R

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so like it becomes like this

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AB=BA=I

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how

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how shld this happen

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i dont understand it

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@misty nebula Has your question been resolved?

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@misty nebula Has your question been resolved?

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@misty nebula Has your question been resolved?

slate barn
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can you condense the question down to like one paragraph

misty nebula
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A belongs to Mn_R

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B belongs to Mn_R

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how does AB=BA=I proves that A is a regular matrix

slate barn
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oh because regular just means it's invertible right

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depends on your original definition but if you have AB = I then B is the inverse to A and you've proved that A is invertible

misty nebula
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oh ok tysm

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thick latch
lone heartBOT
thick latch
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Is my answer for a and b correct

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cause idk what to do with the ln(2)

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cause i need the value to count the error bound

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?

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thick latch
thick latch
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.close

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cloud elk
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help

lone heartBOT
meager rivet
#

help

cloud elk
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chill

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alr so

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yo hello?

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imma js wait

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simplify

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i just need a reminder on how to do this

fleet pawn
cloud elk
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yeah

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the one in the middle

fleet pawn
cloud elk
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wow thank you

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for taking your time to help me

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wait which one is that for

fleet pawn
#

I did
i)

cloud elk
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oh ok

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where did Y go

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.close

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rapid sentinel
#

@here for people who need help with math that is SPECIFIC to economics...
The Edunomix Institute is a not-for-profit organization devoted to expanding access to practical economic education.

This message is being sent to inform you of our upcoming summer camp, which will be centered around entrepreneurship. Our camp will be held virtually and free of charge from July 8-12, 12-2pm EST.

Additionally, there will be two guest speakers this time. One is a CEO of a successful startup and the other is a Forbes Next 1000 finalist!!

Website: edunomixinstitute.com
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Link to Sign Up: https://docs.google.com/forms/d/1tmSbArlRr0JRMjAr8DXxDB2T8XCM-GZoic-E4KOmDQo/viewform?edit_requested=true

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young sundial
lone heartBOT
young sundial
# young sundial

My notes say this has something to do with natural log but I don't have the slightest clue what to do...

median oar
#

What’s the fundamental theorem of calculus?

young sundial
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that much I know. It's the antiderivative part that's tripping me up.

median oar
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What’s the anti derivative of 5/t?

young sundial
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Don't know what to do from here...

hushed locust
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do you know what ln(1) is?

young sundial
#

I got the answer right but I still don't understand what it means...

subtle light
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like what the definite integral represents?

young sundial
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Logarithms, especially natural logs have always been a mystery to me... 5Ln8 might as well be an imaginary number to me.

subtle light
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logarithms are inverse of exponentials

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like lets say we had 10^x

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the inverse function would be log(x)

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natural logs are just with base e

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or the inverse of e^x

young sundial
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Had to flip through old notes to get this...

subtle light
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yep thats showing how they are inverses

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basically the same idea as the square root and the square

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they cancel out each other

ocean sealBOT
young sundial
subtle light
#

then it wouldn’t cancel out

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it depends on what c is

young sundial
#

Alright then... I'll stumble forward from here... Thank you for the help.

#

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fleet pawn
#

How do I find antilog of -4.05

lone heartBOT
fleet pawn
#

I mean how do I find antilog of -ve numbers? Why was +1 and -1 added?

fleet crown
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What is written there

#

?

fleet pawn
fleet pawn
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🤨

fleet crown
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I think I'm starting to decipher it

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log base 10 of ???? = -4.05 - 1 + 1

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is that it?

fleet pawn
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Yes

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But why +1 and -1

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Log(x)to base10=(-4.05)

How do I find antilog of this

fleet crown
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x = 10 to the power of -4.05

fleet pawn
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But I think I don't get answer by solving like that

fleet pawn
#

The +1 -1 thing and 5 bar

fleet crown
#

I can barely read what's written there

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I'd help you but I need some context for this

ocean whale
#

Hard to tell what is going on exactly

fleet pawn
#

Well it is a chemistry question

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I just need help in solving antilog -4.05

ocean whale
#

More context is still needed if you want to understand why + 1 - 1 was done

ocean whale
#

Oh that's pH related

fleet pawn
#

Yes

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So...
How do I solve antilog of -4.05

ocean whale
#

By raising both sides to the power of 10

fleet pawn
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But the guy did +1 -1 and solved

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I want to know that method

ocean whale
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Because log(10) = 1

fleet pawn
#

Calculator are not allowed i need to get the answer in the option

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And if I did 10 to power -4.05 I wouldn't get the answer

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.close

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granite iron
#

how do Iconvert weekly spending to monthy

lone heartBOT
granite iron
#

I keep thinking its just weekly cash amoutx 30 days

vapid drift
#

if a month has 30 days you can do 30 x (weekly spending)/7

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if thats what you mean

granite iron
#

sort off

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its $200 a week being spent and neeed to convertit to montly

alpine sable
#

yeah do what he said

granite iron
#

ill try it

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is it 857.142

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would it be yearly to monthly spedning be 1,000.00/52 weeks?

fleet pawn
granite iron
#

yearly spending to monthly

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i thik its 1,000.00 divided by 12

fleet pawn
#

Divide yearly spending by 12

granite iron
#

thabk you

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close

#

close.

soft pawn
#

.close

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crude grove
#

how can i find the volume of these two hemi-ellipsoids who share the same flat surface, but are different heights?

crude grove
livid sage
#

you apply volume formula (and you may derive it if necessary)

crude grove
#

ok thanks

#

.close

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crude grove
#

.reopen

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hold on

lone heartBOT
#

crude grove
#

wait

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what about surface area?

livid sage
#

surface area of an ellipsoid

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hahahahahahhaaah......

crude grove
#

why is it using the approximately sign

livid sage
#

have you heard those jokes about finding the perimeter of an ellipse

crude grove
#

no im not advanced enough to be laughing at those jokes

livid sage
#

well basically there does not exist a result in elementary functions that you can make use of

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hence why any simple formula you see will have an approximately equal to sign

crude grove
#

oh

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so how would i approximate it

livid sage
#

?

livid sage
crude grove
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at the end

livid sage
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so u use the formula

crude grove
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when my final answer is the approximately something something

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how would i convert it to equal sign

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cause ive seen people approximatingf

livid sage
#

well u can try to set up the integral and numerically approximate an answer like that

crude grove
#

ok i dont want to hear the i-word before i get into gr12

livid sage
crude grove
#

i think ill be fine with approximately 😂

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i'll be rounding it anyway

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rounding is approximation itself

livid sage
#

the formula will be a bit imprecise compared to setting up an integral but

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for ur purposes i assume u don't need a precise answer

crude grove
#

yeah

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itll be in 10ths

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.close

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crude schooner
#

by factorising $e^x(x+2)^2$

ocean sealBOT
#

e=mc^2

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young roost
#

What inequality is this? And is it correct?

young roost
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crude schooner
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noble sinew
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verbal galleon
lone heartBOT
meager rivet
#

for part A
(x+7)(x raise to power 2 - 7x + 49)

unreal meteor
#

cubed root of 343

limpid turret
lone heartBOT
noble ruin
meager rivet
verbal galleon
verbal galleon
meager rivet
fallen verge
#

are you familiar with sum of cubes void?

meager rivet
#

it's a cube+ b cube formula

verbal galleon
meager rivet
#

a^3 + b^3

meager rivet
#

?

fallen verge
#

theres a formula that states
a³+b³ = (a+b)(a²-ab+b²)

verbal galleon
fallen verge
#

yeah

verbal galleon
#

Damn I gotta memorize them again ;-;

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Ok so one sec imma try solving

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(x+7)(x^2-7x+49)

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Am I correct?

fallen verge
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yup

verbal galleon
#

Ayy

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Now for the 2nd

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Is the formula (a-b)(a²+ab-b²)

limpid turret
verbal galleon
#

Oh thanks

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There's no cubic root for 432 tho?

#

<@&286206848099549185>

lone heartBOT
#

@verbal galleon Has your question been resolved?

verbal galleon
#

<@&286206848099549185>

alpine sable
#

Yes?

#

@verbal galleon what do you need help with?

verbal galleon
alpine sable
#

Send me a pic of the questions

verbal galleon
alpine sable
#

Call the gaps A, B and C respectively.

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We get:

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$-2n^3-432=A(n+B)(n^2-6n+C)$

ocean sealBOT
#

Jadεn

alpine sable
#

Factoring:

verbal galleon
alpine sable
#

$-2n^3-432=An^3-6An^2+ACn+ABn^2-6ABn+ABC$

alpine sable
#

that we have to find

ocean sealBOT
#

Jadεn

alpine sable
#

And then you solve using a simple system

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$-2=A,$
$0=-6A+AB,$
$0=AC-6AB,$
$-432=ABC$

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We get the equations from the coeffiecients

ocean sealBOT
#

Jadεn

verbal galleon
alpine sable
#

An = A*n and ACn = A*C*n

#

@verbal galleon

verbal galleon
alpine sable
#

@verbal galleon did you get it?

#

It's just substitution

lone heartBOT
#

@verbal galleon Has your question been resolved?

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mellow iris
#

without diff of cubes how

lone heartBOT
vestal flume
#

Try rewriting sec^2(x) as 1+tan^2(x) on both sides (so it's that cubed on the left)

#

And then see what happens

#

Or if you prefer, you can let u = tan^2(x) so that 1+u = sec^2(x) and do it like that, if it makes moving stuff around easier for you.

lone heartBOT
#

@mellow iris Has your question been resolved?

lone heartBOT
#
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topaz sedge
#

Why is this false? (It is, right?)

lone heartBOT
vestal flume
#

You can't divide in fractions like that

#

You'd need to have x(1+1)/x(x-1)

topaz sedge
#

Can't you just "cancel out" the Xs?

#

Or does that only work when dividing monomes?

pale kestrel
#

try and see with actual numbers

topaz sedge
#

monomials*

jagged cobalt
#

you can only cancel things that are common factors of the numerator and denominator

#

x isnt a factor of '1', or just (x+1) i should say

#

so you cant cancel

pale kestrel
#

,,\frac{2+1}{4-1}=\frac{1+1}{2-1} ???

ocean sealBOT
pale kestrel
#

there is also no such thing as 'cancellation' in math

#

to simplify a fraction, youre usually either adding 0 to it or multiplying it by 1

topaz sedge
#

When you "cancel" you are actually diving both the numerator and denominator by the same value, no?

pale kestrel
#

youre multiplying the fraction by k/k for some k that isnt 0

#

(k/k = 1)

pale kestrel
topaz sedge
#

Hm ok i got it i think

#

So this would be correct?

pale kestrel
#

unusual way to write 46 multiplied by xyz

#

usually the number literal goes first

#

thats correct as long none of x, y, z are 0

topaz sedge
#

So this is possible because you're dividing monomials?

#

Since they are only one term, anything multiplying it is multiplying the whole whing

pale kestrel
#

your dividing the fraction by 1

#

if you like

#

your dividing by (xyz)/(xyz)

#

or youre multiplying by (1/(xyz))/(1/(xyz))

#

i mean yeah what you said i guess...

topaz sedge
#

Ok

#

So, how would you simplify this without using notable products or derivatives?

pale kestrel
#

factorisation

#

no idea why derivatives are relevant at all

topaz sedge
#

For some reason i have a very hard time remembering the notable products, and i haven't learned derivatives just yet

pale kestrel
#

the numerator is linear

#

the denominator is quadratic

#

this highly suggests for you to attempt factorising the quadratic

#

(x + 1)(???) = x^2 - 1

topaz sedge
#

And how do you do that? (Sorry for sounding braindead, it's just that this specific part my math teacher never taught well 😦 )

#

Without having the notable products in your memory

#

This is the kind of thing i mean

pale kestrel
#

well, i suppose one of these is useful

#

but more generally you should be remembering how to expand (a + b)(c + d)

topaz sedge
#

Are you supposed to just remember it, or is there an easier way? I'm terrible at remembering'em

pale kestrel
#

you shouldnt need to remember anything

#

all you need to know is how to expand (a + b)(c + d)

#

using some algebra

pale kestrel
pale kestrel
topaz sedge
#

c(a + b) + d(a + b)

pale kestrel
#

yes, but thats not the full expansion

topaz sedge
#

(c.a + c.b) + (d.a + d.b)

pale kestrel
#

yes, and then the brackets are redundant

pale kestrel
#

for a quadratic

topaz sedge
#

It needs at least an x

#

So it can result in the x squared

pale kestrel
#

whats the general form of a linear term

topaz sedge
#

angular coefficient . independent variable + linear coefficient

#

ax + b, in other words

pale kestrel
#

yes ax + b

pale kestrel
#

so now all you need to do is expand the left side

pale kestrel
#

and substitute in, or do from scratch.

#

it doesnt matter

#

But now theres not as much to memorize right? even if its more work

#

The more you practice (do more work), the more automatically these things will come to memory.

topaz sedge
#

Yes

pale kestrel
topaz sedge
#

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

#

I had trouble figuring out how it would not result in having some x^1

#

Didn't think on the possibility of x - x

#

So the main idea is that you can always express a quadratic by a multiplication of two linears right?

#

So you just need to figure out the coefficients of the specific linear needed

pale kestrel
pale kestrel
#

depends what you mean really

#

you definitely cant factorize all quadratics into two 'nice' linear terms (integer coefficients)

#

you cant even factorize all quadratics into two linear terms with real coefficients, but im not sure if youve come across this

pale kestrel
#

The ones you will be asked about, like in this question, you can factorize nicely though. usually.

topaz sedge
pale kestrel
#

yeah, so it doesnt have a factorization in the reals

#

only with complex coefficients

topaz sedge
#

So in this case you can just replace x with -1, since x=-1 is not a point of discontinuity, right?

#

Gonna eat dinner, might take a while for me to read whatever you answer next

lone heartBOT
#

@topaz sedge Has your question been resolved?

lone heartBOT
#
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crimson island
#

Having trouble evaluating/integrating the following:

ʃcos(ln(x)) dx

My approach right now is let u = ln(x), du = 1/x dx

zinc haven
#

on the right track

bright star
#

can someone help me with this

#

need it done asap

zinc haven
lone heartBOT
# bright star

Someone else is already using this help channel. If you need help with a question, please open your own help channel/thread (see #❓how-to-get-help for instructions).

crimson island
crimson island
#

oh

zinc haven
#

you subbed u=lnx

#

so du=1/x dx

zinc haven
crimson island
#

and dx = xlnu

#

i mean dx = xdu sorry

#

oh ok

zinc haven
#

yes

#

so dx = e^u du

#

now just sub back in

#

that should give you a hint

crimson island
#

ok one second

#

cos(u) e^u du?

#

or no

zinc haven
#

yes

#

$\int e^u\cos u\dd u$

ocean sealBOT
#

your local hot fungus

zinc haven
#

alright

#

what do you think the next step will be?

crimson island
#

i guess du

zinc haven
#

?

crimson island
#

sin u du

zinc haven
#

blud i dont know what youre talking about

crimson island
#

im tryina do integrateion by parts here so i think thats why im confused

#

so i had int u dv = uv - int v du

zinc haven
#

just say ibp

#

ok

crimson island
#

what is ibp

zinc haven
#

integration by part

crimson island
#

oh ok

#

yea so thats where i was stuck so the next step i thought was gona be like v du so sin u du

#

but thats apparently wrong

#

so im stuck

zinc haven
#

i should also say, the u-dv method will be tiring for this

crimson island
#

ok

#

im down for better route

#

im terrible at this

zinc haven
#

Integration by parts by using the DI method! This is the easiest set up to do integration by parts for your calculus 2 integrals. We will also do 3 integrals to illustrate the 3 stops of the DI method.

Dear calculus teachers, please let students use the DI Method (& why it is really the same as integration by parts) 👉 https://youtu.be/8xPfNuXLS...

▶ Play video
crimson island
#

my lowest exam grade was this topic and this is exam review

#

now im worried

#

ok checkin tha now

lone heartBOT
#

@crimson island Has your question been resolved?

crimson island
#

im still stuck

lone heartBOT
#

@crimson island Has your question been resolved?

#
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sharp gust
#

not a specific problem but im wondering when writing out sin/cosine graph equations, knowing which of these two equations to use:

unkempt mica
#

second one is better

#

because then 2pi/|B| is your period

#

and c is the horizontal shift

sharp gust
#

so for a problem like this i would just say

#

oh but its horizontal so make it cos

unkempt mica
#

almost

#

you should write it as

#

but then you can factor out 2pi/40

sharp gust
#

so i should do that even though my phase shift is -pi, does factoring out 2pi/40 not distort that?

unkempt mica
#

it depends on how you view phase shift tbh

#

your actual phase shift is half a turn

sharp gust
#

yeah my actual phase shift is half, so thats the confusing part for me, why you have to factor out the 2pi/40 as that messes with the half turn phase shift

#

a lot of like videos i see of creating an equation from looking at a graph dont factor anything but just put B outside the parenthesis right away

unkempt mica
#

it depends on the type of problem you are trying to solve

#

in this case you look at the circle graph

#

so you gave the phase shift in terms of the unit circle

sharp gust
#

so as a rule of thumb, when looking at a sine/cose graph i can just create the equation how i did, but looking at the circle graph/going around a circle, doing it the other way is better?

unkempt mica
#

you can do it however you like

#

if you know what you are doing both will work

#

for me the phase shift in the problem is 20 seconds (because a whole turn is 40secs) so the equation would be

#

and you can see it clearly on the xy graph :

#

but if you want to think of the phase shift in terms of the unit circle, then write it as

#

both are exactly the same function

sharp gust
#

ahhh okok wait that makes a lot of sense, it really just depends on the problem and what units your graph is in

unkempt mica
#

exactly because in your case you were looking at the circle

#

but sometimes you will be looking at the actual graph of the function

sharp gust
#

yeah, like the picture you showed

#

and in that case it is easy to just see the phase shift is 20 units

unkempt mica
#

thats it

sharp gust
#

that makes sense, tysm

unkempt mica
#

youre welcome

#

also you can check that your answer makes sense by plugging in 0

unkempt mica
#

but you should logically expect -15

sharp gust
#

and if its sine you should get 0 + D and is its cos you should just get D

#

i think

#

thats if you start at the 2pi position of course

unkempt mica
#

im not sure what those letters are

sharp gust
#

for the Asin(Bx-c)+D

unkempt mica
#

oh sure

#

well it depends on the phase shift again

#

but without looking at the equation, think about the fact that you are trying to model the horizontal distance from the center

#

so at t=0 you should get -15, because the carrousel starts at the leftmost point in the circle

sharp gust
#

yeah that makes sense, thank you

#

i think the way im going to do it is when giving a circle use this equation

#

and when your given an actual grpah where you can visibly see the phase shift, this one

lone heartBOT
#

@sharp gust Has your question been resolved?

#
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vestal stag
#

How dod they went from the first highlighted integral to the second one

vestal stag
lone heartBOT
#

@vestal stag Has your question been resolved?

vestal stag
#

I tried to solve the integral separately

lone heartBOT
#

@vestal stag Has your question been resolved?

lone heartBOT
#

@vestal stag Has your question been resolved?

lone heartBOT
#

@vestal stag Has your question been resolved?

vestal stag
#

.close

lone heartBOT
#
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lone heartBOT
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vague gazelle
#

can someone help me illustrate and solve

lone heartBOT
pale glen
#

have you tried drawing the problem

vague gazelle
#

not yet

pale glen
#

try it first

#

you can represent the building with a tall, thin rectangle

#

and maybe the sun on the left

#

meaning, the shadow will form on the right

vague gazelle
#

wait ive tried

#

isnt this will form angle of elevation instead of depression?

pale glen
#

yea youre in the right track

pale glen
#

just form a triangle like that

#

and you can now apply the trigonometry

#

since it wants the angle of depression

#

we essentially want to find this angle

pale glen
#

since thats the angle of depression

vague gazelle
#

what about the measurements

pale glen
#

what did the problem say

#

about the height of the building

#

and the length of the shadow casted

vague gazelle
pale glen
#

yea thats right

#

also draw the things ive drawn as well

vague gazelle
#

what will be used? sin or tan

pale glen
#

what will be the measurements

#

if you are gonna use this triangle

pale glen
vague gazelle
#

whats next

#

wait hold on

#

right?

pale glen
#

yea correct

#

now since that green angle is our reference angle

#

which sides do we have

#

opp?? adj?? hyp??

vague gazelle
#

opp and adj

#

so tan ?

pale glen
#

and what function is that

#

yea

#

tangent

#

alright now write the equation

#

we dont know what the measure of the angle is

vague gazelle
#

tan = 100/300 right

pale glen
#

so lets say its theta

vague gazelle
#

tan x = 100/300

pale glen
#

thats right

#

now how do you solve for x

vague gazelle
#

i forgot what to press 🙏 😭

pale glen
#

well in the left side

#

we are taking the tangent of x

#

to "undo" that function

#

we can take the inverse tangent of both sides

#

like this

#

,,arctan(tan(x))=arctan(\frac{100}{300})

ocean sealBOT
pale glen
#

,,tan^{-1}(tan(x))=tan^{-1}(\frac{100}{300})

ocean sealBOT
pale glen
#

or that

#

they are the same

vague gazelle
#

oh yes i know now

#

hold on

#

soooo 18.43?

pale glen
#

yep

vague gazelle
#

ok thx what about this one

pale glen
#

try to draw it again

vague gazelle
lone heartBOT
#

@vague gazelle Has your question been resolved?

lone heartBOT
#
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vast pecan
#

Vertex on the line 2x - 3y +8=0 focus on the line 4x + y-1=0 y= -1

vast pecan
#

y=-1 is its directrix

#

well witht hat i know it has a vertical axis

#

i just dont know how

north perch
#

the axis is perpendicular to directrix

#

so axis is along y axis

vast pecan
#

yes

#

i already have an answer btw

#

i just dont know how to come up w a solution for it

#

i solved it by graphing

north perch
#

assume the vertex to be (t,(2t+8)/3) and focus as (u,1-4u)

vast pecan
#

where is that coming from

north perch
#

if in first line, x is t then y will be 2t+8/3

#

similarly in second line..

#

did you get it?

vast pecan
#

I dont get

vast pecan
north perch
#

ok suppose that x coordinate of vertex is t

#

then 2t -3y +8=0

#

3y=2t+8

#

y=2t+8/3

#

now?

vast pecan
#

yes

#

but why did u make it t

north perch
#

it looked good

vast pecan
#

Oh

#

ok

#

well the second line

#

u made y u right

#

or still x

north perch
#

x

vast pecan
#

y-1/4

#

oh nvm

#

u just made x u right

north perch
#

yeah

vast pecan
#

4u+y-1=0
y=1-4u

north perch
#

now since axis is vertical, the x cordinate of focus and vertex will be same.

#

so t=u

vast pecan
#

u, 1-4u
t, 2t+8/3

north perch
#

also the vertex is in the middle of directrix and focus

vast pecan
#

so midpoint

north perch
#

yeah

#

1-4u is mid of 2t+8/3 and -1

vast pecan
#

what do i do with the fact that t=u

#

do i just change the variables

#

i pick one then just roll w it

north perch
vast pecan
#

so

#

2u+8/3?

north perch
#

yeah

vast pecan
#

why am i getting

#

1/26 as u

north perch
#

u did smth wrong

#

(8+2u)/3=(-1+1-4u)/2

#

u=-1

vast pecan
#

wait

vast pecan
north perch
#

so u got the focus and the vertex

#

now u can plot axis

vast pecan
#

if u just got the focus and the vertex

#

just get the distance ?

#

of the y

north perch
#

no

vast pecan
#

youll get that as a

#

focal length

north perch
#

wait . what do u want to find out

vast pecan
#

uhhhh just the equation

#

haha

north perch
#

what does the question ask

vast pecan
#

u needa get the equation of the parabola

#

ig

north perch
#

ok

#

then u were doing right

vast pecan
#

whatdu think

#

i was tryna get

north perch
#

the eqn of axis

vast pecan
#

that exists????

#

of

#

oh

#

isnt it just x=-1

#

thats a cool solution

#

i think im done now

#

can i ask an algebra related question

#

y=-4a+1

#

u cant just make it 4a-1 right

#

itd be wrong

north perch
north perch
#

not the other way around

vast pecan
#

yea

#

thx

#

r u like

#

in college

north perch
#

no

#

i am in yr12

vast pecan
#

have u encountered this problem alread

north perch
#

what problem?

vast pecan
#

this problem that we just solved

north perch
#

no

vast pecan
#

but u just knew

#

can we be friends? i really would like to communicate w some person good at maths

#

i like maths too

north perch
#

i am not really online on discord

vast pecan
#

oh alr

north perch
#

today is the first time i opened it in weeks

vast pecan
#

well damn

north perch
#

also entrance exams prep needs time

vast pecan
#

u have entrance exams?

#

where r u from

north perch
#

india

vast pecan
#

well damn

#

good luck bro

#

i heard its hard

north perch
#

thanx

vast pecan
#

r u gonna take

#

JEE

north perch
#

yeah

vast pecan
#

goodluck bro

north perch
#

how did u know

vast pecan
#

idk

#

u said entrance exams

#

and jee is like the test in india so

north perch
#

ohk bye

vast pecan
#

🤷‍♂️

#

.close

lone heartBOT
#
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lone heartBOT
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jade prawn
#

How to do this question?

#

@craggy dagger

zinc haven
#

!15min

lone heartBOT
#

Please only use the <@&286206848099549185> ping once if your question has not been answered for 15 minutes. Please do not ping or DM individual users about your question.

#

@jade prawn Has your question been resolved?

weary birch
#

!status

lone heartBOT
#
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
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strange fractal
#

how would id o part b

lone heartBOT
strange fractal
past musk
#

do -(a+b) then normalize it

strange fractal
#

what does normalise mean

past musk
#

fancy way of saying make it a unit vector

strange fractal
#

oh

#

strange

#

ok thx

#

.close

lone heartBOT
#
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strange fractal
#

.reopen

lone heartBOT
#

strange fractal
#

how come they also have = root 5

#

do u need that

past musk
#

because the length of -(a+b) is root 5

#

you want to make the length 1 so you divide by root 5

strange fractal
#

but its asking for da vector

past musk
#

in general you can get a unit vector by dividing any vector by its magnitude

strange fractal
#

ohh is trhere a formula

#

oh

past musk
#

yeah

strange fractal
#

lol

past musk
#

although i think it's intuitive

strange fractal
#

dam i cant wait for this to get even harder

strange fractal
past musk
#

fancy way of saying "i can mostly see why it is true"

strange fractal
#

oh why?

#

oh so unit vector is just one

past musk
#

well if you multiply a vector by a number it just scales the vector

#

yeah it has length 1

strange fractal
#

so to get one we can divide the vector thingies by

#

the magnitude we get

past musk
#

so for example lets say the vector v has magnitude x, then the vector kv has magnitude kx

#

so if k is 1/x then the magnitude is just 1

strange fractal
#

wait im confused

#

so it'd be -1i + 2j

#

so (-1/sqrt(5), 2/sqrt(5))

past musk
#

-1/sqrt(5) but yes

#

ye

strange fractal
#

oh how come the answer doesnt say it like that

past musk
#

probably because they lazy and they dont like ugly looking fractions inside a vector

#

but mathematically the same

strange fractal
#

is this also the same

#

thats how i'd put it in a test lol

#

wait no

#

GRRRRRRRRRRRR

#

ok ill just do it the ugly way

past musk
#

lol

strange fractal
#

who cares

echo portal
#

ello

strange fractal
#

hi friend

past musk
#

if theyre super duper strict for no reason they migjt also want you to rationalize

echo portal
#

do u want help with smthin?

strange fractal
#

naur im fine

#

RYANCANTPVP IS TO GOOD AT MAFAMATICS

past musk
#

so -sqrt(5)/5, 2sqrt(5)/5

#

no im not

strange fractal
#

if they do im gonna cry

echo portal
strange fractal
#

yes u are..

#

im struggling with this topic sm..

#

my teacher said next year theyre teaching it to us

#

but in 3d

#

pray for me

past musk
#

Ryan, good, and math do not belong in the same sentence

echo portal
past musk
#

idk

echo portal
#

any ways rationalizin is ez

past musk
#

most of the time i see it not rationalized but yeah

#

3D vectors arent that different

echo portal
#

just 1/ sqrt of 5 * -sqrt of 5/-sqrt of 5

echo portal
strange fractal
past musk
#

interesting

strange fractal
#

have i drawn this diagram right

#

for the parallelogram

past musk
#

ive never seen anyone say i cap j cap k cap

#

ive only heard i hat j hat k hat

echo portal
strange fractal
#

grade 10

past musk
echo portal
echo portal
strange fractal
#

yes this is HARD MAN

#

I STARTED 2 DAYS AGO OK

echo portal
#

chill

#

i started 1 day ago

strange fractal
#

😠

past musk
#

to be fair grade 10 is very slightly early for vectors

echo portal
#

bro

strange fractal
#

omg shush ur lips no one cares

echo portal
#

i do vectors at 9th

#

im 9th

past musk
#

good for you

echo portal
#

well they didnt go to adv vectors

#

they taught a lil abt vector algebra

past musk
#

tbh the best way to test if you fully understand vectors is to use it on a bunch of physics

strange fractal
#

but they said no vectors until later sadcat

past musk
#

igcse physics does not use vectors

strange fractal
#

whats igcse

past musk
#

forget i said anythkng im dumb

strange fractal
#

WHAT

#

NO U ARENT WDYM

echo portal
past musk
#

anyways high school physics usually does not involve vectors

#

unless its some super difficult curriculum

strange fractal
#

watt my teacher said we're using vectors later in the year

past musk
#

depends

strange fractal
#

like the f=ma stuff

past musk
#

thats easy

strange fractal
#

yeah

#

i think they introducing it to us and it gets hard in uni idk

#

icl

#

I AM A TINY LITTLE BIT STUCK

past musk
#

i meant stuff like very simple path integrals

past musk
strange fractal
#

yeah i checked my syallabus it says vectors in kinematics

#

wait

strange fractal
past musk
#

i meant using vectors to do actual calculations

strange fractal
#

idk.. im not the brightest student

#

LOL

#

wait

#

ohh i think im getting it

#

bc i dont have BC i can find it using BA+AC

#

and then i can just do

#

1/2(BA+AC)

#

:d

strange fractal
#

Like the PQRS

past musk
#

probably not

lavish cave
past musk
#

as long as its close to the midpoint

lavish cave
#

P is the midpoint of AB

strange fractal
#

OHHHHHHHHH

lavish cave
#

So P has to go on AB and so on

strange fractal
#

thx if they gave me that in a test i wouldnt have known

lavish cave
strange fractal
#

and probs wouldve stuffed the question up

strange fractal
#

the points

lavish cave
#

Yeah, somehow lol

strange fractal
#

yess THX ISAAC NEWTON

#

ok thx guys

#

.close

lone heartBOT
#
Channel closed

Closed by @strange fractal

Use .reopen if this was a mistake.

lavish cave
#

nwnw

lone heartBOT
#
Available help channel!

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Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
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tawny python
#

Hi

lone heartBOT
tawny python
#

.close

lone heartBOT
#
Channel closed

Closed by @tawny python

Use .reopen if this was a mistake.

lone heartBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

sleek timber
#

I’m stuck

lone heartBOT