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AonZ
Group Title
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
 one year ago
 one year ago
AonZ Group Title
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
 one year ago
 one year ago

This Question is Closed

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

AonZ Group TitleBest ResponseYou've already chosen the best response.1
the question asked to solve it using tan3x = sin3x / cos3x :/
 one year ago

AonZ Group TitleBest ResponseYou've already chosen the best response.1
dw:1369139564173:dw
 one year ago

AonZ Group TitleBest ResponseYou've already chosen the best response.1
can you pls post it :) May help me solve it :)
 one year ago

trumpetmaster7777 Group TitleBest ResponseYou've already chosen the best response.1
factor out sin and cos
 one year ago

trumpetmaster7777 Group TitleBest 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)
 one year ago

AonZ Group TitleBest 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
 one year ago

trumpetmaster7777 Group TitleBest ResponseYou've already chosen the best response.1
Pick a trig function, sine or cosine
 one year ago

trumpetmaster7777 Group TitleBest ResponseYou've already chosen the best response.1
Thanks, loser66
 one year ago

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

trumpetmaster7777 Group TitleBest 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)
 one year ago

AonZ Group TitleBest ResponseYou've already chosen the best response.1
yea i actually tried that :P
 one year ago

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

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

AonZ Group TitleBest ResponseYou've already chosen the best response.1
possibly... But you could always change it both ways
 one year ago

AonZ Group TitleBest ResponseYou've already chosen the best response.1
this is the last step i got todw:1369140948450:dw
 one year ago

trumpetmaster7777 Group TitleBest ResponseYou've already chosen the best response.1
1/cos^2(x) is sec^2(x), right?
 one year ago

trumpetmaster7777 Group TitleBest ResponseYou've already chosen the best response.1
use the tangentsecant identity
 one year ago

trumpetmaster7777 Group TitleBest ResponseYou've already chosen the best response.1
1+tan^2(x) = sec^2(x)
 one year ago

AonZ Group TitleBest ResponseYou've already chosen the best response.1
!!!! :D ur awsome
 one year ago

trumpetmaster7777 Group TitleBest ResponseYou've already chosen the best response.1
Thank you :D
 one year ago

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

RolyPoly Group TitleBest ResponseYou've already chosen the best response.0
Would that help? sec^2 = 1 + tan^2
 one year ago
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