Re: [2IIM CAT Prep] question trignometry

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• hi guys....              i think this is the right answer   [tan(63)+tan(27)] - [tan(81)+tan(9)]   = [sin90/(cos63*cos27)]-[sin90/(cos81*cos9)]
Message 1 of 13 , Dec 31, 2008
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hi guys....
i think this is the right answer

[tan(63)+tan(27)] - [tan(81)+tan(9)]

= [sin90/(cos63*cos27)]-[sin90/(cos81*cos9)]

--- On Tue, 2/12/08, vimlesh patelia <vimlesh_21mech@...> wrote:
From: vimlesh patelia <vimlesh_21mech@...>
Subject: Re: [2IIM CAT Prep] question trignometry
To: ascent4cat@yahoogroups.com
Date: Tuesday, 2 December, 2008, 3:09 PM

Hi all,
I don't think the sum of tanØ and tanß would be indeterminate.
If you do it by calcu then also you may come to know.

Regards,
Vimlesh Patelia.

P  please consider the environment before printing this e-mail.

To: ascent4cat@yahoogro ups.com
Sent: Monday, 1 December, 2008 5:14:46 PM
Subject: Re: [2IIM CAT Prep] question trignometry

Apply tanA + tan B = tan (A+B) (1-tanA.tanB)

tan9 + tan81 - (tan27 + tan63)

tan90.(1 - tan9.tan81) - tan90.(1 - tan27.tan63)

Infinity - Infinity

Indeterminate.

~Cheers,
Haneef.

On Sat, Nov 29, 2008 at 6:53 PM, bharadwaja y wrote:
 hi clarify my doubt,tan9-tan27-tan63+ tan81=need srt cut

• well the correct solution is here ( i am writing down this solution becuz michael arun`s equations and ans are different his equations give negative ans but
Message 2 of 13 , Jan 3, 2009
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well the correct solution is here ( i am writing down this solution
becuz michael arun`s equations and ans are different his equations
give negative ans but the ans is positive and also to remove sum
confusion abt formulas of trignometry)
TAN9 -TAN27 -TAN63 +TAN81
USE THE FORMULA
TAN(A)+TAN(B)=SIN(A+B)/COS(A)COS(B)
the domain for this formula is A  nÎ and B  Î
so use this on 9 and 81 & the other group wud be 27 and 63
NOTE:- we cannt use the formula
TAN(A+B)=TANA-TANB/1+TANA*TANB
cuz the domain for this formula is AnÎ+Î/2 BmÎ+Î/2
and A+BkÎ+Î/2
so the question of infinity doesnt arise cuz u cant use this formula
on the group (9,81) and (27,63) cuz the sum is =Î/2
more over - isnt infinity , its indeterminate and theres a
difference between indeterminate quatity and infinity
+ means that its lager than all the real numbes however large it may
be , we dont know its value so how can u find its difference thats y
the difference cant be found hence its called inderterminate and that
is not equal to infinity
so using the formula
TAN(A)+TAN(B)=SIN(A+B)/COS(A)COS(B)
sin90/cos9cos81 - sin90/cos27cos63
now multiply numerator and denominator by 2
2/2cos9cos81 - 2/2cos27cos63
now use the formula 2cosAcosB=cos(A+B)+cos(A-B)
and also remember that cos(-Æ)=cosÆ
so it boils down to
2/cos72 - 2/cos36
i hope u guys know that cos36=(1/4)(ã5+ 1 )
cos72=2cos^2(32)-1
so now put the values
my ans came to be abt 4.002

tc all
and happy new year
RAHUL SAINI

>
> On Sat, Nov 29, 2008 at 6:53 PM, bharadwaja y
>
> > hi clarify my doubt,
> >
> > tan9-tan27-tan63+tan81=
> >
> > need srt cut
> >
> >
> >
>

>
>
> On Sat, Nov 29, 2008 at 6:53 PM, bharadwaja y
>
> > hi clarify my doubt,
> >
> > tan9-tan27-tan63+tan81=
> >
> > need srt cut
> >
> >
> >
>
• well the correct solution is here ( i am writing down this solution becuz michael arun`s equations and ans are different his equations give negative ans but
Message 3 of 13 , Jan 3, 2009
• 0 Attachment
well the correct solution is here ( i am writing down this solution
becuz michael arun`s equations and ans are different his equations
give negative ans but the ans is positive and also to remove sum
confusion abt formulas of trignometry)
TAN9 -TAN27 -TAN63 +TAN81
USE THE FORMULA
TAN(A)+TAN(B)=SIN(A+B)/COS(A)COS(B)
the domain for this formula is A ≠ nπ and B ≠ π
so use this on 9 and 81 & the other group wud be 27 and 63
NOTE:- we cannt use the formula
TAN(A+B)=TANA-TANB/1+TANA*TANB
cuz the domain for this formula is A≠nπ+π/2 B≠mπ+π/2
and A+B≠kπ+π/2
so the question of infinity doesnt arise cuz u cant use this formula
on the group (9,81) and (27,63) cuz the sum is =π/2
more over ∞-∞ isnt infinity , its indeterminate and theres a
difference between indeterminate quatity and infinity
+∞ means that its lager than all the real numbes however large it may
be , we dont know its value so how can u find its difference thats y
the difference cant be found hence its called inderterminate and that
is not equal to infinity
so using the formula
TAN(A)+TAN(B)=SIN(A+B)/COS(A)COS(B)
sin90/cos9cos81 - sin90/cos27cos63
now multiply numerator and denominator by 2
2/2cos9cos81 - 2/2cos27cos63
now use the formula 2cosAcosB=cos(A+B)+cos(A-B)
and also remember that cos(-θ)=cosθ
so it boils down to
2/cos72 - 2/cos36
i hope u guys know that cos36=(1/4)(√5+ 1 )
cos72=2cos^2(32)-1
so now put the values
my ans came to be abt 4.002

tc all
and happy new year
RAHUL SAINI

>
> On Sat, Nov 29, 2008 at 6:53 PM, bharadwaja y
>
> > hi clarify my doubt,
> >
> > tan9-tan27-tan63+tan81=
> >
> > need srt cut
> >

--- In ascent4cat@yahoogroups.com, michael arun <mma_gct@...> wrote:
>
> hi guys....
> Â Â Â Â Â Â Â Â Â Â Â Â  i think this is the right answer
> Â
> [tan(63)+tan(27)] - [tan(81)+tan(9)]
> Â
> = [sin90/(cos63*cos27)]-[sin90/(cos81*cos9)]
>
> =4.503..... check with your formulas....
> Â
> Â
>
> --- On Tue, 2/12/08, vimlesh patelia <vimlesh_21mech@...> wrote:
>
> From: vimlesh patelia <vimlesh_21mech@...>
> Subject: Re: [2IIM CAT Prep] question trignometry
> To: ascent4cat@yahoogroups.com
> Date: Tuesday, 2 December, 2008, 3:09 PM
>
>
>
>
>
>
>
>
>
> Hi all,
> I don't think the sum ofÂ tanÃ and tanÃÂ would be indeterminate.
> If youÂ do it by calcu then also youÂ mayÂ come to know.
> Â
> Regards,
> Vimlesh Patelia.
>
> P Â please consider the environment before printingÂ this e-mail.
>
>
>
>
>
>
> From: Haneef Mohammad <haneef0786@gmail. com>
> To: ascent4cat@yahoogro ups.com
> Sent: Monday, 1 December, 2008 5:14:46 PM
> Subject: Re: [2IIM CAT Prep] question trignometry
>
>
>
> Apply tanA + tan B = tan (A+B) (1-tanA.tanB)
>
> tan9 + tan81 - (tan27 + tan63)
>
> tan90.(1 - tan9.tan81) - tan90.(1 - tan27.tan63)
>
> Infinity - Infinity
>
> Indeterminate.
>
> ~Cheers,
> Haneef.
>
>
>
> On Sat, Nov 29, 2008 at 6:53 PM, bharadwaja y <bharadwajasharma_
y@...> wrote:
>
>
>
>
>
>
>
>
>
>
>
> hi clarify my doubt,
> tan9-tan27-tan63+ tan81=
> need srt cut
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
http://messenger.yahoo.com/invite/
>
• hi guys.... i think this is the right answer [tan(63)+tan(27)] - [tan(81)+tan(9)] =4
Message 4 of 13 , Jan 7, 2009
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hi guys....
i think this is the right answer
[tan(63)+tan(27)] - [tan(81)+tan(9)]
=4
• tan90 is not equal to zero, its infinity. Sandeep IIT MADRAS ... From: amit jain Subject: Re: [2IIM CAT Prep] question trignometry To:
Message 5 of 13 , Jun 16, 2009
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tan90 is not equal to zero, its infinity.

Sandeep

--- On Mon, 1/12/08, amit jain <amitjain3325@...> wrote:

From: amit jain <amitjain3325@...>
Subject: Re: [2IIM CAT Prep] question trignometry
To: ascent4cat@yahoogroups.com
Date: Monday, 1 December, 2008, 6:59 PM

check formula of tan a + tan b as here 63+27= 90 & 81+7 = 90. the trick lies their. i think answer will be zero bcoz of that very reason pl. confirm the same.

Regards
Amit