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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
 11 months ago
 11 months 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
 11 months ago
 11 months ago

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

AonZBest ResponseYou've already chosen the best response.1
the question asked to solve it using tan3x = sin3x / cos3x :/
 11 months ago

AonZBest ResponseYou've already chosen the best response.1
can you pls post it :) May help me solve it :)
 11 months ago

trumpetmaster7777Best ResponseYou've already chosen the best response.1
factor out sin and cos
 11 months ago

trumpetmaster7777Best 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)
 11 months ago

AonZBest ResponseYou've already chosen the best response.1
my 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
 11 months ago

trumpetmaster7777Best ResponseYou've already chosen the best response.1
Pick a trig function, sine or cosine
 11 months ago

trumpetmaster7777Best ResponseYou've already chosen the best response.1
Thanks, loser66
 11 months ago

trumpetmaster7777Best ResponseYou've already chosen the best response.1
so, let's go with sine cos^2(x)=1sin^2(x), right?
 11 months ago

trumpetmaster7777Best ResponseYou've already chosen the best response.1
plug in (1sin^2(x)) for cos^2(x) (sinx)(34sin^2(x))/((cosx)(4cos^2(x)3)
 11 months ago

AonZBest ResponseYou've already chosen the best response.1
yea i actually tried that :P
 11 months ago

AonZBest ResponseYou've already chosen the best response.1
after doing that would you divide by cos^2 x?
 11 months ago

trumpetmaster7777Best ResponseYou've already chosen the best response.1
wait up look at the tan(3x) expression can't you clean that up a bit?
 11 months ago

AonZBest ResponseYou've already chosen the best response.1
possibly... But you could always change it both ways
 11 months ago

AonZBest ResponseYou've already chosen the best response.1
this is the last step i got todw:1369140948450:dw
 11 months ago

trumpetmaster7777Best ResponseYou've already chosen the best response.1
1/cos^2(x) is sec^2(x), right?
 11 months ago

trumpetmaster7777Best ResponseYou've already chosen the best response.1
use the tangentsecant identity
 11 months ago

trumpetmaster7777Best ResponseYou've already chosen the best response.1
1+tan^2(x) = sec^2(x)
 11 months ago

trumpetmaster7777Best ResponseYou've already chosen the best response.1
Thank you :D
 11 months ago

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

RolyPolyBest ResponseYou've already chosen the best response.0
Would that help? sec^2 = 1 + tan^2
 11 months ago
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