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#1 2015-01-09 09:24:37

BonaviaFx
Member
Registered: 2014-12-15
Posts: 11

Trigonometric Identities Problem

I'm Stuck on this one:

tan^2x-sin^2x ≡ sin^4x*sec^2x

Need some help hmm

Last edited by BonaviaFx (2015-01-09 09:24:56)

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#2 2015-01-09 21:19:36

Bob
Administrator
Registered: 2010-06-20
Posts: 10,627

Re: Trigonometric Identities Problem

hi BonaviaFx

I just give the hints so you can finish this yourself.  smile

tan = sin/cos so use this to 'remove' the tan and factorise a sin term.

When you factorise, the remaining bracket needs to be over a single denominator.

Then sin^2 = 1 - cos^2 will enable you to simplify what remains.

Bob


Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob smile

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#3 2015-01-11 04:36:28

BonaviaFx
Member
Registered: 2014-12-15
Posts: 11

Re: Trigonometric Identities Problem

How about from the RHS:

RHS=Sin^2xSin^2xSec^x

(1-Cos^2x)Sin^2x(1/Cos^2x)

(Sin^2x/Cos^2x)-(Cos^2xSin^2x/Cos^2x)

Tan^2x-Sin^2x

Correct?

I Used the RHS because I still didn't manage from the LHS.

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#4 2015-01-11 07:11:57

Bob
Administrator
Registered: 2010-06-20
Posts: 10,627

Re: Trigonometric Identities Problem

hi BonaviaFx

Yes, That looks ok to me.  smile

Bob


Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob smile

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#5 2015-01-11 08:23:03

BonaviaFx
Member
Registered: 2014-12-15
Posts: 11

Re: Trigonometric Identities Problem

Thanks smile

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