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jpjones
Group Title
solve the following equation for x where
0<or = to x<2pi, sin2x=cosx
 2 years ago
 2 years ago
jpjones Group Title
solve the following equation for x where 0<or = to x<2pi, sin2x=cosx
 2 years ago
 2 years ago

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Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.3
hint: \(sin2x = 2sinxcosx\)
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.3
well where are you stuck or show me what you did
 2 years ago

jpjones Group TitleBest ResponseYou've already chosen the best response.0
the equation is not solved
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.3
\[ 2sinxcosx = cosx => 2sinxcosx  cosx = 0 \] why dont you try and solve it
 2 years ago

sami21 Group TitleBest ResponseYou've already chosen the best response.1
take cos(x) you will have \[\Large \cos(x)[2\sin(x)1]=0\] now you have two equations \[\Large \implies \cos(x)=0\] \[\Large \implies 2\sin(x)1=0\] solve these two equations.
 2 years ago

jpjones Group TitleBest ResponseYou've already chosen the best response.0
if i knew how to solve these equations i wouldn;t be asking for help
 2 years ago

jpjones Group TitleBest ResponseYou've already chosen the best response.0
to this stage i know, but how to solve from here?
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.3
\[\cos(x) = 0 => cosx = \cos\left(\frac{\pi}{2}\right) => x = \frac{\pi}{2} +n*2\pi , n \epsilon\mathbb{Z} \] \[sinx = \sin\left(\frac{\pi}{6}\right) => x = \left(1\right)^{n}*\frac{\pi}{6} +n*\pi , n \epsilon\mathbb{Z} \]
 2 years ago

jpjones Group TitleBest ResponseYou've already chosen the best response.0
i've been to wolfram alpha to mimi
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.3
lol i didnt use wolfram..
 2 years ago

jpjones Group TitleBest ResponseYou've already chosen the best response.0
the answer is correct though but i have to show it using the unit circle, or the graph
 2 years ago

jpjones Group TitleBest ResponseYou've already chosen the best response.0
i think using the sin wave
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.3
dw:1345619287591:dw
 2 years ago

sami21 Group TitleBest ResponseYou've already chosen the best response.1
ok let me give you an example then if you have 2cos(x)+1=0 then \[\Large \implies \cos(x)=\frac{1}{2}\] \[\Large x=\cos^{1}(\frac{1}{2})\] there are only two points in 9o.2pi) for which cos(x) is 1/2 they are \[\Large x=\frac{2 \pi}{3}\] \[\Large x=\frac{4 \pi}{3}\] now solve the 2sin(x)1=0 its quite similar to this.
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.3
for sinx dw:1345619404355:dw
 2 years ago

sami21 Group TitleBest ResponseYou've already chosen the best response.1
you use wolfram,thats why you are unable to solve these equations by yourself. this wolfram thingy has ruined the students :(. i think at this level students should avoid using that.
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.3
yeah i agree. you should only use it to check your answers
 2 years ago

jpjones Group TitleBest ResponseYou've already chosen the best response.0
no i dont use it but i am aware of it
 2 years ago

jpjones Group TitleBest ResponseYou've already chosen the best response.0
mimi you've been great i think i should become a fan
 2 years ago
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