#Calculus

112 messages · Page 1 of 1 (latest)

undone linden
#

Im confused how to solve this

twilit gazelleBOT
#
  1. Wait patiently for a helper to come along.
  2. Once someone helps you, say thank you and close the thread with:
+close
  1. Feel free to nominate the person for helper of the week in #helper-nominations
  2. Do not ping the mods, unless someone is breaking the rules.
  3. If you're happy with the help you got here, and the server overall, you can contribute financially as well:
limber light
#

Mm i prefer logarithmic differtiation

#

That will simplify your answer

#

Btw you have to use product rule

undone linden
#

i have not learned that,

undone linden
limber light
#

X and root 900-x

#

Two dif terms

undone linden
#

but thats chain rule

limber light
#

No its product rule

undone linden
#

but the 900-x has the power of 1/2

limber light
#

That is chain rule

#

But first you have to aply product rule

undone linden
#

that looks like an overload profile picture

limber light
#

Oh yes i drew it

#

If you know log i can teach you a more elegant method

undone linden
# limber light

im not sure i understand, i thought of the terms givin as chain rule becasue of the squre root

limber light
#

Oh ok

#

So here x is one function dependent on the variable and root of 900 -x is one more function

undone linden
#

there is no way we use product rule

#

can't be

limber light
undone linden
#

can we do it with chain rule?

limber light
#

No chain rule is different

#

When you do d/dx of f(x) you use chain rule

#

Chain rile is only when there is one function that is complex

#

So now try using this

#

And find the answer

#

I will wait

#

Any problems?

undone linden
#

yes,

#

well i was doing side research on chain rule rq to try and figure stuff out

#

it honestly does look like I can do chain rul e

limber light
#

No

#

Its not like chain rule

#

In chain rule a function is inside another function

#

Like 900-x a function is inside a root function

#

X on the other hand is not

#

It is just multiplied

undone linden
#

, are you trying to say x represents its own term making x and the squarroot functino only differntiable with product rule

limber light
#

Yep

#

Soooo got the answer?

undone linden
#

one sec

#

yeah i couldn't

limber light
#

You made a slight mistake

#

In second part it is -x

#

900-x

#

@undone linden

#

Then you just equate to zero and you will get correct answer

undone linden
limber light
#

Like you wrote 900+x

#

Instead of 900-x

undone linden
#

ohhh

undone linden
limber light
#

Derivate is equal to zero as they are asking to find maxima

limber light
#

Here i am saying

#

Mm do you habe any question?

undone linden
#

isolate for x i assume but that seems like a long process

limber light
#

No it is not

#

Very simple

#

Let me show you

undone linden
#

it does seem hard

limber light
#

Nah its just 2 step process

#

I elaborated it so that you can understand the steps

undone linden
#

interesting

#

so the (900 - x) cancel out

limber light
#

Not cancel out

undone linden
#

well\

#

combine

limber light
#

Yep

#

Its like √x*√x

#

=x

undone linden
#

yep

#

alright and then after i get my x, which is 600

#

whats next?

limber light
#

Just input the value in pi of x

#

Cause you found value at which it is max

#

Now you have to find the maximum value

undone linden
#

ah

#

we solved for x

#

so jus plug x back in and find profit

limber light
#

Yep

undone linden
#

nice, thank you

limber light
#

Just tell me the final answer so i can cross check it

undone linden
#

A

limber light
#

Yeah ok nice

undone linden
#

also

limber light
#

Just sp you know here is an elegant way of solving

undone linden
#

natural logs instead of logs?

limber light
#

Without any chain rule product rule

#

Yeah cause differentiation

#

Of ln x is 1/x

#

We dont need any extra terms like base and all

undone linden
#

yeah

#

you are right

#

does log differnetiaon work with all problems?

limber light
#

It is suitable for those with many functions multiplied

#

Some case implicit is better

undone linden
#

i see

#

also