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#1 2012-12-01 00:19:33

unlucky guy
Guest

proving identities

my teacher is evil and won't explain everything. he wants brides and stuff like that... he gave only one easy example about trigonometric function and gave 48 exercises as a homework including problems.

please can u help me with this one...

prove that sin t + sec t = tan t is not an identity.                and please with little bit more explanation about how you solving

#2 2012-12-01 00:42:43

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 88,791

Re: proving identities

Hi unlucky guy;

One of the easiest ways is to find an obvious counterexample:

so sec(0)  is 1 / 1 because cos(0) is 1.

because


In mathematics, you don't understand things. You just get used to them.

I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.

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#3 2012-12-01 01:02:59

unlucky guy
Guest

Re: proving identities

thanks smile

#4 2012-12-01 01:06:34

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 88,791

Re: proving identities

Hi;

Please let me know what your evil teacher thinks of it. He sounds like a moderator I know on another forum. If they are the same, he will absolutely hate my answer...


In mathematics, you don't understand things. You just get used to them.

I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.

Offline

#5 2012-12-01 03:11:51

unlucky guy
Guest

Re: proving identities

no he isn't tongue im sure

#6 2012-12-01 08:17:35

bobbym
Administrator
From: Bumpkinland
Registered: 2009-04-12
Posts: 88,791

Re: proving identities

Hi;

Okay, good luck then and welcome to the forum.


In mathematics, you don't understand things. You just get used to them.

I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.

Offline

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