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anonymous
 one year ago
Could someone please explain how to find an exact value of sin(11pi/12)? I'm not sure how to get them in the answer as the ones given:
A. (Sq. Rt 2  Sq. Rt 6)/4
B. (/Sq. Rt 6  Sq. Rt 2)/4
C. (Sq. Rt 6  Sq. Rt 2)/4
D. (Sq. Rt 6 + Sq. Rt 2)/4
anonymous
 one year ago
Could someone please explain how to find an exact value of sin(11pi/12)? I'm not sure how to get them in the answer as the ones given: A. (Sq. Rt 2  Sq. Rt 6)/4 B. (/Sq. Rt 6  Sq. Rt 2)/4 C. (Sq. Rt 6  Sq. Rt 2)/4 D. (Sq. Rt 6 + Sq. Rt 2)/4

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.011pi/12 is half of 11pi/6, so you can use a half angle identity. \[\sin \frac{ \theta }{ 2 }=\sqrt{\frac{ 1\cos \theta }{ 2 }}\] where Θ=11π/6

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ok, but how can I get the answers like the ones I was given?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Because I simplified the problem to: 2pi/3 + pi/4. But I'm not sure how to get them simplified to what answers I am given.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0you used a different identity, so you got the answer in a different format. The easiest way to get the answer in the root of a root format is to use the half angle identity

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0ok so you used the \(\sin(a + b) = \sin a \cos b + \cos a \sin b \) identity?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0what did you get when you did it?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Well, I only have right now, 2pi/3 + pi/4

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0you have to substitute the values you got into the equation and evaluate it\[\sin \frac{ 11\pi }{ 12 }=\sin(\frac{ 2\pi }{ 3 }+\frac{ \pi }{ 4 })=\sin \frac{ 2\pi }{ 3 }\cos \frac{ \pi }{ 4}+\cos \frac{ 2\pi }{ 3 }\sin \frac{ \pi }{ 4 }\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Ok, but how can I get it to the root of a root form?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0it looks like you don't have to do that, and if you use the unit circle to find those value it will give you the answer

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So, I'm still a little confused what to do with sin2π3cosπ4+cos2π3sinπ4

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0what's sin (2pi/3)? Use your unit circle?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0right. Now do cos π/4

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so far we have (√3)/2 * (√2)/2

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0great :). now do the other 2
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