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AonZ
 2 years ago
Pls Pls Pls help... I have been stuck for a while!!!
Prove
tan3x = (3tanx  tan^3 x) / ( 1  3tan^2 x)
using sin3x/ cos3x = tan3x
sin3x = 3sinx  4sin^3 x
cos3x = 4cos^3 x  3cosx
AonZ
 2 years ago
Pls Pls Pls help... I have been stuck for a while!!! Prove tan3x = (3tanx  tan^3 x) / ( 1  3tan^2 x) using sin3x/ cos3x = tan3x sin3x = 3sinx  4sin^3 x cos3x = 4cos^3 x  3cosx

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.Sam.
 2 years ago
Best ResponseYou've already chosen the best response.0Have you tried using\[\tan(3x)=\tan(2x+x)\] Then \[\tan(A+B)=\frac{tanA+tanB}{1tanAtanB}\]

AonZ
 2 years ago
Best ResponseYou've already chosen the best response.1the question asked to solve it using tan3x = sin3x / cos3x :/

AonZ
 2 years ago
Best ResponseYou've already chosen the best response.1can you pls post it :) May help me solve it :)

trumpetmaster7777
 2 years ago
Best ResponseYou've already chosen the best response.1factor out sin and cos

trumpetmaster7777
 2 years ago
Best ResponseYou've already chosen the best response.1(3sinx  4sin^3 x)/(4cos^3 x  3cosx) (sinx)(34sin^2(x))/((cosx)(4cos^2(x)3)

AonZ
 2 years ago
Best ResponseYou've already chosen the best response.1my way was to factor out sin and cos so it was tanx times something then i divided the numerators by cos^2 x then im stuck

trumpetmaster7777
 2 years ago
Best ResponseYou've already chosen the best response.1Pick a trig function, sine or cosine

trumpetmaster7777
 2 years ago
Best ResponseYou've already chosen the best response.1Thanks, loser66

trumpetmaster7777
 2 years ago
Best ResponseYou've already chosen the best response.1so, let's go with sine cos^2(x)=1sin^2(x), right?

trumpetmaster7777
 2 years ago
Best ResponseYou've already chosen the best response.1plug in (1sin^2(x)) for cos^2(x) (sinx)(34sin^2(x))/((cosx)(4cos^2(x)3)

AonZ
 2 years ago
Best ResponseYou've already chosen the best response.1yea i actually tried that :P

AonZ
 2 years ago
Best ResponseYou've already chosen the best response.1after doing that would you divide by cos^2 x?

trumpetmaster7777
 2 years ago
Best ResponseYou've already chosen the best response.1wait up look at the tan(3x) expression can't you clean that up a bit?

AonZ
 2 years ago
Best ResponseYou've already chosen the best response.1possibly... But you could always change it both ways

AonZ
 2 years ago
Best ResponseYou've already chosen the best response.1this is the last step i got todw:1369140948450:dw

trumpetmaster7777
 2 years ago
Best ResponseYou've already chosen the best response.11/cos^2(x) is sec^2(x), right?

trumpetmaster7777
 2 years ago
Best ResponseYou've already chosen the best response.1use the tangentsecant identity

trumpetmaster7777
 2 years ago
Best ResponseYou've already chosen the best response.11+tan^2(x) = sec^2(x)

AonZ
 2 years ago
Best ResponseYou've already chosen the best response.1on denominator its still sec^2  4tan^2 ... errr im lost again

RolyPoly
 2 years ago
Best ResponseYou've already chosen the best response.0Would that help? sec^2 = 1 + tan^2
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