Ask
your own question, for FREE!
Mathematics
8 Online
OpenStudy (anonymous):
use sum-to-product to find EXACT VALUE of sin150degrees + sin30degrees
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
why can't you just add them?
OpenStudy (anonymous):
\[\sin(150)=\frac{1}{2}\]
\[\sin(30)=\frac{1}{2}\]
\[\frac{1}{2}+\frac{1}{2}=1\] finis
OpenStudy (anonymous):
It seemed too easy lol. and I kept getting either 1 or 0 .
OpenStudy (anonymous):
it is pretty darned easy considering the other ones
OpenStudy (anonymous):
Well it says I have to use the sum- to- product formula
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
then pretend to use it and write 1 as the answer
OpenStudy (anonymous):
xD kay . I got a verifying identity i can't solve >.<
OpenStudy (anonymous):
ok ok
so we have to have
\[\sin(\alpha+\beta)+\sin(\alpha-\beta)=2\sin(\alpha)\cos(\alpha)\] right?
OpenStudy (anonymous):
mhmm
OpenStudy (anonymous):
so lets see
\[\alpha +\beta=150\]
\[\alpha -\beta=30\] solve and get
\[2\alpha =180\implies \alpha =90\] and so
\[\beta =60\]
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
and in it goes:
\[2\sin(90)\cos(60)=2\times 1\times \frac{1}{2}=1\]
OpenStudy (anonymous):
lotta work for that simple answer i would say
OpenStudy (anonymous):
xD I appreciate it though
Can't find your answer?
Make a FREE account and ask your own questions, OR help others and earn volunteer hours!
Join our real-time social learning platform and learn together with your friends!