differentiation help

[quick zinc]

Help help help differentiation help

[viscid pumice]

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[grave sonnet]

This is just nonsensical. You can't have an equation as a term in an expression.

[quick zinc]

Well

This is the full question

[grave sonnet]

Clearly this isn't the whole context.

[quick zinc]

And I know I have to form a chain equation

I’ve gotten dS/dr

I’m trying to form dS/dl now

So I can form dS/dt

This is the answer

And I don’t know how that

sqrt(l^2 -25) came

This is what I got

[jovial sorrel]

I suspect they meant something along the lines of

S, which equals π(l²-25)

• πl√(l²-25)

[quick zinc]

Yes that’s what it means

[jovial sorrel]

So you want to differentiate $\pi\qty(l^2-25)+πl\sqrt{l^2-25}$

With respect to l

[verbal blaze]

yoavmal

[quick zinc]

Yes

[jovial sorrel]

Left part is easy

Right part less so

What is the derivative of $cf(x)$ where $c$ is a constant?

[verbal blaze]

yoavmal

[quick zinc]

c*f’(x)

[jovial sorrel]

@quick zinc

[quick zinc]

Dem

What

I replied

[jovial sorrel]

Discord at its best

Ok, so in our case we can do that with the left part

Where c=π

[jovial sorrel]

Yeah I see

[jovial sorrel]

So what's the derivative of just the left part?

[quick zinc]

What I wrote down here

The first term

[jovial sorrel]

Ok, and second term is a product

[jovial sorrel]

It's not chain rule but product rule

[quick zinc]

What product rule to make a chain equation is what I meant to say

[jovial sorrel]

Oh

[quick zinc]

Yea fuck mathematical terms

[jovial sorrel]

¯_(ツ)_/¯

Either way

Lets be organized about it

Do you recall the precise phrasing of the product rule?

[quick zinc]

Yes

Wait as in the

Definition of

What product rule I have to use here

[quick zinc]

Really I’m just asking how that sqrt(l^2-25) came

[jovial sorrel]

How to differentiate it or

Where did it come from?

[quick zinc]

Where’d it come from

OH MY GOD

FUCKING

INTEGRATION BY PARTS

I CANG BELIEVE I SPENT THIS MUCH TIME

FUCK THSI SHIT

GOOD BYE

Actually

Noel

[jovial sorrel]

What?

[quick zinc]

Obv that isn’t it

It

[jovial sorrel]

Geometrically?

[quick zinc]

Cause I have to differentiate it

Not integrate it

Idkkk

Ugh

[jovial sorrel]

Are you asking how to differentiate it or

Where did that term come from

Deriving that equation

[quick zinc]

WHERE DOES IT COME FROM

[jovial sorrel]

Lets see

It's a sqrt of two squares

[quick zinc]

Ok

[jovial sorrel]

What in geometry has squares?

Added or subtracted?

[quick zinc]

huh

Pythagoras theorem

[jovial sorrel]

Yeah probably

[jovial sorrel]

Try spotting which length here corresponds to that

[quick zinc]

What

I also don’t think that’s it yoav

I already found that part

[jovial sorrel]

Then wdym where did it come from

[quick zinc]

The one I wrote here

[quick zinc]

And this is the answer

[jovial sorrel]

Product rule

[quick zinc]

Idk where that came from

[jovial sorrel]

What's the derivative of f(x)g(x)?

[quick zinc]

Idr could you tell me

[jovial sorrel]

f'g+g'f

$f'(x)g(x)+g'(x)f(x)$

[verbal blaze]

yoavmal

[quick zinc]

Oh

Damn all that time for that simple mistake

I should just kms

Thanks yoav for your time

[jovial sorrel]

Keep yourself safe yeah

+close