Math Is Fun Forum

ilovealgebra

Member

Registered: 2006-10-02

Posts: 40

multi var. calc

Just a quick problem... My solution was 0, just making sure this is correct

z=(cosh(xy))^2 ; x=(t/2) , y=e^t    Find dz=dt

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"...nothing physical which sense-experience sets before our eyes, or which necessary demonstrations prove to us, ought to be called into question (much less condemned) upon the testimony of biblical passages."
-Galileo Galilei

ilovealgebra

Member

Registered: 2006-10-02

Posts: 40

Re: multi var. calc

that was x = (t/2)

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"...nothing physical which sense-experience sets before our eyes, or which necessary demonstrations prove to us, ought to be called into question (much less condemned) upon the testimony of biblical passages."
-Galileo Galilei

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: multi var. calc

Hi ilovealgebra;

With those substituions:

This can be simplified to:

Can you differentiate that?

Last edited by bobbym (2009-11-24 12:42:18)

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

ilovealgebra

Member

Registered: 2006-10-02

Posts: 40

Re: multi var. calc

Ah ok, so final answer would then be:  dz/dt = (1/2)sinh(te^t)[e^t + te^t] ?

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"...nothing physical which sense-experience sets before our eyes, or which necessary demonstrations prove to us, ought to be called into question (much less condemned) upon the testimony of biblical passages."
-Galileo Galilei

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: multi var. calc

Hi;

Yep, that is what I am getting.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

ilovealgebra

Member

Registered: 2006-10-02

Posts: 40

Re: multi var. calc

ok excellent, cheers for the help, also what level of education do u have atm? just curious

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"...nothing physical which sense-experience sets before our eyes, or which necessary demonstrations prove to us, ought to be called into question (much less condemned) upon the testimony of biblical passages."
-Galileo Galilei

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: multi var. calc

Hi ilovealgebra;

The best in the country. But a teacher forced me out by saying that I reasoned like a dog.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.