Mathematics
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OpenStudy (anonymous):
find solution in the interval [0,2pi): sin(2x)= sqrt3/2
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OpenStudy (anonymous):
do you have a link?
OpenStudy (bluemiku):
there's no link?
OpenStudy (anonymous):
no
OpenStudy (anonymous):
i can rewrite it for you:\[find solution \in the interbal [0,2\pi): \sin(2x)=\frac{ \sqrt{3}}{ 2 }\]
OpenStudy (anonymous):
whoops, it supposed to say find in the intervals [0,2pi). Not sure what happened when I wrote the equation lol
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jimthompson5910 (jim_thompson5910):
If you used the unit circle, what is the value of t that makes sin(t) = sqrt(3)/2 true?
OpenStudy (anonymous):
11pi/6
jimthompson5910 (jim_thompson5910):
11pi/6 is in Q4 where sine is negative
OpenStudy (anonymous):
pi/6?
jimthompson5910 (jim_thompson5910):
closer but no
sin(pi/6) = 1/2
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jimthompson5910 (jim_thompson5910):
we want the sine value to be sqrt(3)/2
OpenStudy (anonymous):
pi/3
jimthompson5910 (jim_thompson5910):
good, sin(pi/3) = sqrt(3)/2
jimthompson5910 (jim_thompson5910):
what other value of t makes sin(t) = sqrt(3)/2 true?
OpenStudy (anonymous):
2pi/3
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jimthompson5910 (jim_thompson5910):
correct
jimthompson5910 (jim_thompson5910):
so if
sin(2x) = sqrt(3)/2
then
2x = pi/3 or 2x = 2pi/3
jimthompson5910 (jim_thompson5910):
add on "+2pi*n" to capture all coterminal angles
if
sin(2x) = sqrt(3)/2
then
2x = pi/3+2pi*n or 2x = 2pi/3+2pi*n
jimthompson5910 (jim_thompson5910):
n is any integer
OpenStudy (anonymous):
ok, thank you!
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jimthompson5910 (jim_thompson5910):
what is the next step
OpenStudy (anonymous):
oh theres more? lol..hmm, I don't know. This is the first time I've had a 2x in sine.
OpenStudy (anonymous):
divide by 2?
jimthompson5910 (jim_thompson5910):
you have 2x = ....
you want x = ...
jimthompson5910 (jim_thompson5910):
yes you divide everything by 2
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jimthompson5910 (jim_thompson5910):
or better yet, multiply everything by 1/2
jimthompson5910 (jim_thompson5910):
2x = pi/3+2pi*n
(1/2)*2x = (1/2)*(pi/3)+(1/2)*2pi*n
x = pi/6 + pi*n
OpenStudy (anonymous):
pi/6+pi*n and 2pi/6+pi*n?
jimthompson5910 (jim_thompson5910):
2x = 2pi/3+2pi*n
(1/2)*2x = (1/2)*(2pi/3)+(1/2)*2pi*n
x = pi/3 + pi*n
OpenStudy (anonymous):
ohh! Ok.
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jimthompson5910 (jim_thompson5910):
if
sin(2x) = sqrt(3)/2
then
2x = pi/3+2pi*n or 2x = 2pi/3+2pi*n
that turns into
x = pi/6 + pi*n or x = pi/3 + pi*n
where n is any integer
jimthompson5910 (jim_thompson5910):
you need to now generate particular solutions by plugging in values of n
make sure that x is in the interval [0, 2pi)