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OpenStudy (jojokiw3):
How do I do this trig question?
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OpenStudy (jojokiw3):
\[\cos (\frac{ -13\pi }{ 6 }) + \sin \frac{ 13\pi }{ 6 }\]
OpenStudy (jdoe0001):
hmmm I'd guess you simply get their values and add them up :)
OpenStudy (jdoe0001):
since it's not really an equation anyway
OpenStudy (xapproachesinfinity):
you can use
\[13\pi/6=2\pi +\pi/6\]
use then the fact that sin and cos are 2pi periodic
OpenStudy (xapproachesinfinity):
yah i guess too
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OpenStudy (jojokiw3):
\[\frac{ \sqrt{3} + 1 }{ 2 }?\]
OpenStudy (xapproachesinfinity):
you have cos(-x)=cos(x)
so you just get rid of - sign for cos (-13pi/6)
OpenStudy (xapproachesinfinity):
hmm not quite
OpenStudy (xapproachesinfinity):
what is sin pi/6
OpenStudy (xapproachesinfinity):
and cos pi/6
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OpenStudy (jdoe0001):
\(\bf cos \left( -\cfrac{ 13\pi }{ 6 } \right) + sin \left( \cfrac{ 13\pi }{ 6 } \right)
\\ \quad \\
cos(-\theta)=cos(\theta)\qquad thus
\\ \quad \\
cos \left( -\cfrac{ 13\pi }{ 6 } \right) + sin \left( \cfrac{ 13\pi }{ 6 } \right)\iff cos \left( \cfrac{ 13\pi }{ 6 } \right) + sin \left( \cfrac{ 13\pi }{ 6 } \right)\)
OpenStudy (xapproachesinfinity):
eh hold on i guess you are correct my bad
OpenStudy (jojokiw3):
Haha lol. I was panicking for a moment there.
OpenStudy (xapproachesinfinity):
root 3+1 /2 is good
OpenStudy (jojokiw3):
Thanks guys. :) I appreciate the help.
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OpenStudy (jdoe0001):
yw
OpenStudy (xapproachesinfinity):
yw
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